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Animal Production Science

Animal Production Science

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A high-concentrate diet commonly causes digestive disorders in finishing lambs. This study aimed to evaluate effects of sugar beet pulp and canola seeds on ruminal fermentation and morphology of finishing lambs. Partial use of sugar beet pulp and roasted canola seed inclusion successfully optimized ruminal environment and had beneficial effects on morphology of the rumen in lambs fed a high-concentrate diet.

Dietary supplementation of 3-nitrooxypropanol (NOP) has been suggested as an effective strategy to lower enteric methane (CH4) emissions from ruminants. Results from the present study further support the efficacy of NOP in lowering CH4 emissions. Among various dose levels investigated in the present study, NOP supplemented at 100, 150 and 200 mg/kg DM was the most effective in decreasing CH4 emissions in steers fed high-forage and high-grain diets, without inducing any negative effects on intake.

Studies of greenhouse gas emissions (GHGE) in agriculture rarely account for the variation that occurs due to seasonal conditions. This study quantified the effects of climate variability and stocking strategies on GHGE and profit of a northern Queensland beef herd. Moderate stocking rates had the lowest GHGE intensity and highest profit, supporting previous work that recommends similar stocking strategies in the region.

The present study analyses New Zealand data on methane emissions from sheep fed fresh grass-based diets, collected between 2009 and 2015, where emissions were measured using respiration chambers. Dry matter intake alone was found to be a good predictor of emissions, although in animals <1 year of age the inclusion of dietary metabolisable energy concentration in addition to dry matter improved predictions.

The people of the world demand high-quality diets containing animal products, and the demand for those products is projected to increase; meeting that demand requires improved efficiency of use of valuable feedstuffs. Achieving those improvements is complicated by the complexity of animal biology, but that complexity can be addressed in silico through mechanistic simulation models. Future models should be directed to effects of disease, activation of the immune system, various stressors and health-improving technologies.

AN15425Effect of measurement duration in respiration chambers on methane traits of beef cattle

P. F. Arthur, K. A. Donoghue, T. Bird-Gardiner, R. M. Herd and R. S. Hegarty

Cattle emit methane, a greenhouse gas, which is usually measured in specialised facilities over 2 or more days. We have demonstrated that the measurement can be done in 1 day with less than 5% loss in accuracy. The resulting increase in throughput of the facilities means that more cattle can be measured for this important gas.

AN15632A review of whole farm-system analysis in evaluating greenhouse-gas mitigation strategies from livestock production systems

Richard Rawnsley, Robyn A. Dynes, Karen M. Christie, Matthew Tom Harrison, Natalie A. Doran-Browne, Ronaldo Vibart and Richard Eckard

Livestock forms an important component of global food production and is a significant contributor to anthropogenic greenhouse-gas (GHG) emissions. This paper reviews how whole farm-system modelling has been used to assess GHG mitigation strategies for livestock production. Whole farm-system modelling provides an effective and efficient means for quantifying the benefits farmers are delivering through changing farm management practices.

Methane emissions from ruminants are a significant contributor to climate change and are produced by archaeal methanogens. Due to their unusual metabolism, gene- and enzyme-based techniques can be used to develop methanogen-specific inhibitors, using strategies similar to those employed to develop anti-cancer drugs. We review previous research that has incorporated chemically defined inhibitors against methanogens and discuss the impacts on future control of ruminant methane emissions.

κ-CN plays a critical role in the formation and stabilisation of casein micelles, and influences the manufacturing properties of milk. Although genotypes for κ-CN polymorphisms were associated with protein and solids-not-fat content of milk in Hostein and Brown Swiss, they had an effect on fat content of milk in Jersey. B allele was associated with increasing milk quality, therefore, selection of B allele could provide economic advantage for increasing milk quality.

Increases in the efficiency of microbial protein synthesis (EMPS) of cattle grazing tropical pastures should lead to increased liveweight gain through increased total metabolisable protein supply. Rumen degradable protein (RDP) supply from tropical pastures is low; hence, increasing the dietary supply of RDP is a strategy to increase EMPS. Our study showed that only high amounts of RDP supply to the rumen, in the form of true protein, resulting in increased EMPS. However, at lower intakes of RDP, which were formulated to achieve EMPS in the range suggested in the feedings standards, there was no difference in supplying the RDP as non-protein nitrogen or degradable true protein.

Twenty young Cika and 20 Simmental bulls were finished post-weaning on two diets and slaughtered at similar carcass weights. Cika bulls produced carcasses with a higher dressing percentage, more fat and less tendons and bones. The Longissimus thoracis muscle of Cika bulls had a lower pH, higher redness, yellowness and drip loss, and a more intense flavour.

Hay, an essential component of dairy cow rations, is required for rumen function and milk fat. Testing the influence of fibre and sugars on a cow’s decision to choose between hays showed that the fibre content of the hay was a dominant factor and further, decisions made in the first 30 min were indicative of longer-term choice; composition of total hay intake also contributed to choice. The results provide a basis for improved ration formulation.

AN16210Assessing and mitigating post-operative castration pain in Bos indicus cattle

M. Laurence, A. Barnes, T. Collins, T. Hyndman and G. C. Musk

Bos indicus cattle are often castrated after six months of age without pain relief. Measures of pain that include pedometry, blood cortisol concentrations, and baulk and crush scores were used to characterise post-surgical castration pain and determine whether perioperative lignocaine or meloxicam or both reduced pain. Pedometer measures and cortisol concentrations proved useful and showed that strategic use of analgesics is viable in extensive farming situations and provides benefit to animals undergoing castration.

Ruminal pH is a critical factor that could affect rumen fermentation efficiency; thereby, rumen buffer should be considered. Banana flower power-pellet could enhance rumen ecology and fermentation efficiency. This study suggests that banana flower powder pellet is potentially used as a rumen buffer agent for high-producing cattle, promising to replace sodium bicarbonate.

We showed the genetic and phenotypic correlations between economic traits and selection indices, besides the expected genetic gains. Selection for better body composition should provide increase in scrotal circumference and weight gain. The use of indices should result in a positively correlated response for indirectly selected traits. Higher genetic gains to visual scores are expected when the selection is based on the values of these indices.

Methane emissions from ruminant livestock (cattle, buffalo, sheep and goat) were estimated at ~2.2 billion tonnes of carbon dioxide equivalent, accounting for ~80% of agricultural methane and 37% of the total anthropogenic methane emissions. The present study was designed to evaluate the effects of plants as methane inhibitors in growing buffaloes. Methane emission was inhibited by ~10–18% in the supplemented groups. Further, long-term experiments should be conducted to validate these findings before they can be recommended for use at a field level.

Phosphorus has nutritional, environmental and economic importance due to its high cost and potential for soil and water contamination. We evaluated the effect of phosphorus supplementation, with or without other minerals, ionophore and antibiotic, on animal performance, feeding costs and phosphorus utilisation in Nellore bulls finished in a feedlot. Minerals, ionophore and antibiotic were not necessary to ensure health and performance of feedlot Nellore bulls, with emphasis for the reduction of pollution and feeding costs in Brazilians feedlots.

To improve productive performance, the findings of this study should be useful for the feed and broiler chicken industry. The present study was conducted to investigate the effect of reducing dietary protein with methionine supplementation and subsequent feeding of a low-energy diet on growth performance of broiler chickens. The results indicate that growth performance and carcass quality were significantly improved by this method, which may be an appropriated tool for improving production of broiler chickens.

What is effect of yeast preparations on fatty acids and flavour which are closely related to beef quality? A research was conducted, of which results indicated that yeast products had little effect on individual fatty acid but improved the tenderness of beef. The findings will be beneficial in regulating beef quality by yeast preparations in the near future.

Artificial pollen substitutes are needed to improve honeybee productivity in periods of nutrient scarcity during droughts, wet weather, gaps in floral sources and when bees are working eucalyptus flows with limited- or poor-quality pollen. Ingredients meeting honeybee nutrient requirements were screened for attractiveness and tested as a sole nutrient source. Bee-collected pollen outperformed the artificial substitutes and further modification to the substitutes is required.

An in-depth understanding of energy and protein partitioning, underpinning nutrient utilisation, is pivotal for allowing predictions of growth in animals based on knowledge of nutrients in diets. A construct to allow a logical quantitative study of nutrient partitioning in the growing animal from a causal perspective is discussed. Gaps in current knowledge are identified.

AN16351Performance and behaviour of Nellore steers on integrated systems

L. F. Domiciano, M. A. Mombach, P. Carvalho, N. M. F. da Silva, D. H. Pereira, L. S. Cabral, L. B. Lopes and B. C. Pedreira

Animal performance and behavioural responses were evaluated under different production systems, throughout two seasons. Time of the day and especially the seasons influenced behavioural responses and animal performance. Meat production can be increased when the system includes rotation with crops (soybean and maize). Silvopastoral systems provide Nellore steers with a more comfortable and preferred environment for idleness and rumination.

Return on investment from animal research in Australia is about half that from investment in crop research. These returns could be improved by (1) selection of more appropriate areas for research, (2) adoption and consistent application through a risk-control system of a small number of processes that, if not performed correctly, will have large impacts on productivity and (3) strict adherence to the scientific method. Future application of electronic technologies for measurement, interpretation and control of farm processes in real-time through web-based systems will enhance productivity and free managers from day-to-day operations for long-term strategy development.

Phosphorus deficiency in cattle grazing rangelands may have severe adverse effects. Single photon absorptiometry was used in on-farm experiments to measure tail-bone mineral density and thus diagnose bone phosphorus. Prolonged phosphorus deficiency markedly reduced mineral density of tail-bone in young-growing and reproducing cattle, but not in mature cows. Single photon absorptiometry may be valuable to diagnose long-term phosphorus deficiency in cattle.

AN16122Evaluating the economics of concentrate feeding decisions in grazing dairy cows

C. K. M. Ho, J. W. Heard, W. J. Wales, J. L. Jacobs, P. T. Doyle and B. Malcolm

Feeding concentrates so that the marginal cost of extra feed closely matches the marginal revenue from extra milk produced should enable dairy farmers to feed supplements profitably. In the present study, a farm in northern Victoria was used to analyse the economics of tactical (short-term) and strategic (medium- to longer-term) decisions about concentrate feeding. The results show that making decisions about supplementary feeding using marginal analysis adds more to farm profit than making decisions on the basis of other criteria, such as feeding supplement for maximum milk production.

In Australia, animal excreta deposited onto pasture by grazing livestock is a major source of nitrous oxide, a potent greenhouse gas. Field studies found that emissions of nitrous oxide from excreta could be reduced by up to 59% by the application of the chemical inhibitor, nitrapyrin. Nitrapyrin was found to be an effective tool in reducing emissions from dung, urine and dairy sludge and was most effective on wet soils.

AN16221Metabolic changes during brief periods of ewe–lamb separation at different ages

P. Mora-Medina, A. Orihuela-Trujillo, P. Roldan-Santiago, E. Arch-Tirado, C. Vázquez-Cruz and D. Mota-Rojas

Improving our knowledge of the physiological characteristics of ovine species in stressful situations during the neonatal phase will be of great economic importance for livestock production. Breaking the ewe–lamb bond at different ages and for brief separation times triggers metabolic changes in young animals. The greatest physiological alterations occurred in the parameters of the youngest lambs, after a separation of 10 min from their mothers. Younger lambs suffered greater metabolic changes in contrast to older lambs.

The greenhouse gas methane can be absorbed or emitted by soil while cattle wastes deposited onto the soil can be a source. In field studies, the effect of applications to pasture of dung and dairy sludge on net methane emissions to the atmosphere were examined. Measured emissions were mostly lower than those currently used in the current Australian estimates for emissions from dairy cow dung in temperate Australia.

Adjusting the porosity of beddings can improve their ability to produce heat. The type of fungal-residue media has no effect on the growth performance of pigs. Smaller bedding granules may lead to pig cough. Fungal-residue bedding can partly replace sawdust in bedding. Bedding added 45% fungal residue can improve the welfare of pigs during winter.

In extensive production systems, native pasture availability decreases in winter, thus, ewes are undernourished during gestation. We subjected pregnant ewes to two different levels of pasture allowances, both followed by an increase in nutrient supply during the last third of gestation. Ewe-lamb behaviours at birth, lambs’ growth and feeding behaviours during rearing were unaffected by the level of pasture allowance.

Dietary restriction result in accelerated body growth in pigs during re-feeding, but it is not clear whether this phenomenon is due to changes in metabolic hormones, lipid deposition or protein metabolism. Effect of dietary protein restriction on the body growth and blood content of some metabolic hormones as markers of lipid or protein metabolism was studied. During the re-feeding, increased daily weight gains and concentrations of plasma leptin and urea nitrogen were observed, indicating greater lipid deposition and protein breakdown.

In recent years, dairy cattle breeders have shown an increasing interest in selection for functional traits such as calving difficulty. The aim of the present study was to estimate genetic correlation between calving difficulty and productive and reproductive performance of Holstein cows. Exploitable genetic variation in calving difficulty, productive and reproductive traits could be applied in designing future genetic selection plans for Iranian Holsteins.

AN16419Growing goats of different sexes have distinct metabolic responses to continuous feed restriction

Nhayandra C. D. Silva, Carla J. Härter, Fernanda O. M. Figueiredo, Rafael F. Leite, José M. Santos Neto, João A. Negrão, Izabelle A. M. A. Teixeira and Kléber T. Resende

One of the main nutritional challenges imposed on animals is feed restriction; however, it is still unknown how goats of different sexes react physiologically to the continuous restriction of nutrients. This study investigated the effect of sex on metabolic changes in growing goats subjected to levels of feed restriction. Our results show that under feed restriction, females and males react differently physiologically and are able to use different metabolic responses to meet their energy and protein demands.

AN15642Verification of micrometeorologically determined nitrous oxide fluxes following controlled release from pasture

M. J. Harvey, S. E. Nichol, A. M. S. McMillan, R. J. Martin, M. J. Evans and A. M. Bromley

Emissions of the greenhouse gas nitrous oxide arise following deposition of excretal nitrogen from cattle grazing on pasture. Accurate measurement is challenging because the emissions can be very variable in time and space; paddock-scale methods can capture and integrate through this variability. We present here the first experiment to independently verify a paddock-scale emission method with a known emission of nitrous oxide. We show that emission is likely to be under-estimated using uncorrected vertical concentration-difference measurements.

AN16303Feed efficiency and enteric methane production of Nellore cattle in the feedlot and on pasture

L. F. Oliveira, A. C. Ruggieri, R. H. Branco, O. L. Cota, R. C. Canesin, H. J. U. Costa and M. E. Z. Mercadante

Residual feed intake has been recommended as a selection criterion for beef cattle to increase individual feed efficiency. Efficient or low residual feed-intake cattle have a significant economic advantage since they consume less feed than expected for their weight and rate of gain compared with their more inefficient or high residual feed-intake counterparts. The results do not support the hypothesis that an increase in feed efficiency, evaluated in growing animals in feedlot-performance tests, decreases enteric CH4 production.

AN16628Effects of high concentrations of crude glycerin in diets for feedlot lambs: feeding behaviour, growth performance, carcass and non-carcass traits

Marco Tulio Costa Almeida, Jane Maria Bertocco Ezequiel, Josimari Regina Paschoaloto, Henrique Leal Perez, Vanessa Barbosa de Carvalho, Edivilson Silva Castro Filho and Eric Haydt Castello Branco van Cleef

Glycerin is the main by-product of the biodiesel industry and it is considered an attractive source of energy in livestock diets. Variations in corn prices make studies like the present one even more relevant. Total corn replacement could be possible depending on glycerin market price, as high inclusions (30%) reflect in greater number of days on feed. The addition of 10% of crude glycerin in diets for crossbred finishing lambs seems to be the most interesting strategy as it promotes greatest performance.

AN16556Characteristics of carcasses and meat from feedlot-finished buffalo and Bos indicus (Nellore) bulls

J. L. M. Mello, A. B. B. Rodrigues, A. Giampietro-Ganeco, F. B. Ferrari, R. A. Souza, P. A. Souza and H. Borba

Buffalo meat is still considered exotic in Brazil, and ~90% of it is marketed as cattle meat. The present study compared qualitative characteristics of the longissimus muscle from buffalo and cattle. Buffalo carcasses provide a higher yield of round cuts. Meat from buffalo carcasses had similar or better properties than that from cattle carcasses, and is a rich source of some hypocholesterolemic fatty acids, which help prevent cardiovascular diseases.

AN15755Parity and grazing-time effects on milk fatty acid profile in dairy cows

E. Morales-Almaráz, B. de la Roza-Delgado, A. Soldado, A. Martínez-Fernández, A. González, I. A. Domínguez-Vara and Fernando Vicente

Dairy cows with several calvings would have a healthier milk fat than would cows in their first calving. The present study was conducted to investigate the effects of parity on the fatty acid profile in milk fat from dairy cows with different grazing times. Although the milk from primiparous cows had a lower fat content, it had a higher grade of unsaturation than did milk from multiparous cows, so their milk could be considered as healthier milk.

AN15765Protection of α-amylase from proteolysis by adsorption to feed components in vitro and in the porcine small intestine

Anton M. Pluschke, Paulus G. M. Jochems, Barbara A. Williams and Michael J. Gidley

Digestion of feed nutrients in the small intestine of, for example, pigs involves enzymes specific for their substrate, for example, protein or starch, but these reactions take place in the presence of all other feed components. The effects of diet components on the activity of digestive enzymes was studied, and it was found that binding of enzymes to non-substrate feed components is both rapid and highly effective in stabilising enzymes against degradation. These results mean that studies of factors that control the rate of digestion of specific feed nutrient substrates need to take into account the possibility of interactions with non-substrate feed components.

The large intestine is a part of the gastrointestinal tract of pigs that is the most colonised by bacteria and its proper function is crucial for the maintenance of animal welfare and performance. Activity and composition of bacterial flora may be changed by feed additives such as inulin. Our results indicate that inulin, regardless of dietary level and degree of polymerisation, does not stimulate beneficial bacteria and immune system of the large intestine of young pigs.

AN16013Variation in instrumental meat quality among 15 muscles from 14-month-old sheep and its relationship with fibre typing

Javier Ithurralde, Gianni Bianchi, Oscar Feed, Fernando Nan, Fernando Ballesteros, Gustavo Garibotto and Alejandro Bielli

Muscle fibres are the main components of meat and their characteristics are crucial for meat quality. We studied the associations between fibre typing and meat quality across 15 young-sheep muscles and found that although fibre diversity may explain, at least in part, intermuscular differences in meat quality, these associations can also slightly vary in sense among different contractile–metabolic groups of muscles. The present study has contributed to a better understanding of the influence of muscle fibre types on intermuscular meat-quality variation.

Flystrike causes losses due to sheep deaths and loss of production. This study quantifies the loss of weight, condition, wool and lamb production in flocks in a wide range of regions of Australia. The results can be used to estimate losses due to flystrike and potential benefits of preventing strike or reducing its severity.

Increasing ruminal input of buffers from the diet or saliva yields bases or buffers such as ammonia could prevent a depression in ruminal pH. Supplementation of banana flower powder either with or without urea could enhance rumen ecology and fermentation efficiency. Therefore, banana flower powder is potentially used as a rumen buffer agent for high-producing dairy cattle promising to replace sodium bicarbonate.

AN15864Associative effects between Arachis pintoi and dwarf elephantgrass hays on nutritional value in sheep

A. C. Dall-Orsoletta, T. Reiter, G. V. Kozloski, V. Niderkorn and H. M. N. Ribeiro-Filho

The inclusion of forage legumes in ruminant production systems presents nutritional, economic and environmental benefits. The aim of the present study was to evaluate the effect of different levels of inclusion of peanut hay on the nutritional value of diets based on dwarf elephantgrass hay. It was found that including peanut hay at up to 330 g/kg of dry matter in dwarf elephantgrass-based diets is sufficient to maximise the digestible-OM intake.

AN16098Optimising finishing pig delivery weight: participatory decision problem analysis

F. Leen, A. Van den Broeke, M. Aluwé, L. Lauwers, S. Millet and J. Van Meensel

For science to be effectively valorised in practise, stakeholders should be part of the research process. In this study, a management problem in pig production was analysed with stakeholders, which led to guidelines on how to perform such a process. These guidelines can well be considered in any research effort aiming at practical implementation of its results.

The organic acids that were regarded as substitutes for antibiotics have recently been applied to decrease the proliferation of acid-intolerant enteropathogenic bacteria. This research investigated the influences of dietary sodium diacetate on growth performance, carcass characteristics, meat quality, and intestinal pH and Escherichia coli count of broilers. Results suggest that dietary sodium diacetate could improve growth performance, meat quality and intestinal health of broilers.

AN16319Fatty acid profile, oxidative stability and sensory quality of breast meat from turkeys fed diets with graded levels of flaxseed oil for different periods of time

Jan Jankowski, Zenon Zduńczyk, Dariusz Mikulski, Jerzy Juśkiewicz, Janusz F. Pomianowski and Przemysław Zduńczyk

A very high n-6 : n-3 ratio, as is found in today’s Western diets, promotes the pathogenesis of many diseases in consumers. The results of our study indicate that the recommended n-6 : n-3 polyunsaturated fatty acid ratio in turkey breast meat may be easily reached if birds are fed 2.5% flaxseed oil for the last 3 weeks before slaughter. Therefore, such a feeding program with a relatively low application of dietary flaxseed oil could be considered a suitable delivery vehicle for health-promoting fatty acids.

Copy number variations (CNVs) have been known as one of the most important sources of variation in animal genome. In this study, a total of 957 CNVs was detected across autosomal genome of Iranian indigenous cattle using high-density single nucleotide polymorphism genotyping data. Results of this study provide a base for further investigation on genetic markers affecting the important production traits in Iranian indigenous cattle.

Efficiency of pasture use by beef cattle enterprises in southern Australia is traditionally ~35% because of a low adoption of existing knowledge and perceived risks from intensification. Principles from a risk-control system aimed at enhancing adoption were incorporated into a simple simulation model and applied to an enterprise on the central tablelands of New South Wales. Alternative management scenarios to optimise productivity and maximise profitability were evaluated and showed that interacting factors within an enterprise are too complex to effectively identify best strategies without the use of a system to integrate knowledge.

Breech strike cost the Australian industry more than AU$200 million per year. Factors responsible for an increase in breech strike were investigated in unmulesed Merinos in a production system where no chemical preventative treatments were applied. Dags in uncrutched sheep and tail wrinkle in crutched sheep were the two most important predisposing factors for breech strike but a large proportion of the variation in breech strike in unmulesed and uncrutched sheep could not be explained.

AN16061Effect of growth path on the performance and carcass traits of Hereford steers finished either on pasture or in feedlot

Elisa Peripolli, Georgget Banchero, Angélica Simone Cravo Pereira, Gustavo Brito, Alejandro La Manna, Enrique Fernandez, Fabio Montossi and Fernando Baldi

There is no information available about how differences in growth rate before the finishing phase affect animal performance and carcass attributes of cattle finished under temperate conditions. The objective of the present study was to assess the effect of nutritional management during the rearing period on the performance and carcass traits of pasture-finished or feedlot-finished Hereford cattle. Nutritional feeding management during the first winter has a permanent effect on the growth, feed conversion traits, and carcass traits. However, the prevalence of these effects depends on the feeding system during the finishing phase of animals.

AN16108Genetic correlation between growth and reproductive performance of beef females depends on environment

Mário L. Santana, Joanir P. Eler, Annaiza B. Bignardi, Arione A. Boligon and José B. S. Ferraz

Growth and reproductive traits of beef cattle are important economically and, therefore, are commonly included in selection indices. In tropical production systems, beef cattle are raised in highly heterogeneous environments. It has been shown that genetic associations between growth traits and reproductive performance are dependent on the production environment; thus, the genotype by environment interaction is important for genetic evaluations and can affect selection of these traits.

The assignment of maternal parentage, although time-consuming and expensive using traditional methods, is essential for genetic improvement. The temporal frequency that cows and calves walk to water was measured to determine whether maternal pairs could be remotely identified and resulted in greater than 90% of calves being correctly assigned. This has the potential to greatly increase maternal parentage recording within extensive beef herds, therefore identifying superior genetics and resulting in more profitable beef enterprises.

Reduction of enetric methane production from ruminant animals through the use of natural plant products is important because it causes global warming and energy loss to animals. Medicinal plant extracts, when tested on feed in the laboratory, reduced both enetric methane produced and energy loss by increasing feed digestibility. These plants can be used as replacements for artificial growth promoters in the meat and dairy industries to prevent antibiotic resistance syndrome in humans consuming animal products and animals can achieve faster maturity weight with lower methane emissions.

We investigated the effects of stocking rate and supplementary feeding on the performance of grazing ewes in pregnancy/lactation, and on their lambs. Both treatments had significant effects on intake and liveweight responses, but there were also marked effects of initial condition score and dentition score of ewes. In future work, more attention needs to be paid to these scores as important explanatory variables.

Pasture-based dairy operations allow for natural grazing behaviour; however, suboptimal nutrition may be more difficult to prevent due to variable quality of natural forages. The present study aimed to evaluate the effects of pregnant-cow management on colostrum quality, dairy calf health and growth. Cow weight loss during the dry period, an indicator of suboptimal nutrition, had a negative impact on colostrum quality but did not directly affect calf health and growth.

AN16580Castration methods in crossbred cattle raised on tropical pasture

Aline D. Moreira, Gustavo R. Siqueira, Josiane F. Lage, João Marcos B. Benatti, Matheus H. Moretti, Giulianna Z. Miguel, Ivanna M. de Oliveira and Flávio D. de Resende

Alternative methods to improve performance and carcass traits, considering animal welfare. The aim was to compare surgical castration and immunocastration in beef cattle raised on pasture. Immunocastration can replace surgical castration and is an efficient method to improve carcass traits. The castration methods improve meat quality and carcass finishing; however, intact animals present greater production capacity.

When animals are exposed to a high level of stress, the animal’s body undergoes physiological changes as a means of maintaining homeostasis, thus negatively affecting the quality of meat produced. This study investigated breed and sex differences in response to pre-slaughter stress and the effects on stress indicators in the blood, muscle and overall meat quality attributes. The ewes and Dorper breed perceived the slaughter process to be more stressful compared with rams and the Merino breed.

AN16128Influence of zeolite (clinoptilolite) supplementation on characteristics of digestion and ruminal fermentation of steers fed a steam-flaked corn-based finishing diet

J. D. Urías-Estrada, M. A. López-Soto, A. Barreras, J. A. Aguilar-Hernández, V. M. González-Vizcarra, A. Estrada-Angulo, R. A. Zinn, G. D. Mendoza and A. Plascencia

Because of their sorbent properties and binding capacity with ammonia, natural zeolites may have application as feed additive in livestock industry. Our results indicate that zeolite supplementation of high finishing diets enhances ruminal fermentation and increases digestion.

Previous work has shown canola and wheat have potential as dual-purpose crops to support animal liveweight gain and grain production in animals other than dairy heifers. Limited information is available regarding the use of canola and wheat to support dairy heifer production and its effect on environment sustainability. This study investigated liveweight gain and urinary nitrogen excretion of dairy heifers grazing canola and wheat in comparison to perennial ryegrass-white clover pasture. The results indicate that canola and wheat can sustain heifer liveweight gain, while potentially reducing nitrous oxide emissions and nitrate leaching compared with pasture.

Livestock contributes to global warming by emission of greenhouse gases (GHGs). In the process of fermentation of feed in the fore stomach, dairy animals produce methane. Majority of dairy animals in developing countries are fed on rations imbalanced in nutrients. As a result, animals on such rations produce more methane per litre of milk. On feeding balanced rations, animals produce less enteric methane and manure nitrous oxide. Thus, balanced feeding could be a promising strategy for reducing GHGs emission intensity.

Methane production of sheep in pastoral systems is a major contributor to total greenhouse gasses produced in New Zealand. Elevated water-soluble carbohydrate concentrations, as in high sugar (HSG) and tetraploid (TRG) ryegrass, may affect rumen fermentation and reduce methane production per unit of intake, as found in this study for sheep fed HSG and TRG. However, the effect was not consistently associated with either cultivar and could not be attributed to higher forage water-soluble carbohydrate concentrations.

AN15563Changes in feed intake during isolation stress in respiration chambers may impact methane emissions assessment

Pol Llonch, Shane M. Troy, Carol-Anne Duthie, Miguel Somarriba, John Rooke, Marie J. Haskell, Rainer Roehe and Simon P. Turner

Methane, a major greenhouse gas emitted by livestock, requires robust methods of measurement in order to identify new and appropriate mitigation strategies. This study demonstrates that isolation within respiration chambers, the current most precise method of methane measurement in livestock, could underestimate emissions due to a reduction in feed intake. If changes in behaviour and physiology due to isolation stress are modelled, this would refine estimations of livestock greenhouse gas emissions that will help to find the most appropriate measures to mitigate climate change.

Chronic inflammation is a common yet underappreciated feature of intensive livestock production systems and is also associated with exposure to high environmental temperatures. Recent research in the medical field has shown that methyl donors can prevent or ameliorate inflammatory diseases such as fatty liver and enteritis. It is proposed that supplementation of livestock diets with methyl donors such as betaine, choline or folate may be effective in the prevention and treatment of chronic inflammation and associated diseases in livestock.

Dairy cows are in some ways very much like human consumers; they select from among a variety of foods on the basis of the nutritive characteristics of those foods. When a cow is offered two oaten hays simultaneously, we provide a means of predicting how much of each hay will be consumed. Accurate prediction of hay intake will enable the selection of a set of hays that maximises the nutritive value of what dairy cows consume, and thereby maximises milk production.

The low fibre, high β-carotene and protein contents in lucerne leaf-meal (LLM) make it an attractive substitute forage for commercial calf feeding. The present study assessed the performance of pre-weaned Holstein heifers supplemented with LLM. Holstein heifer calves with forage provision (LLM) had higher nutrient intake and greater growth performance than the control diet. These results confirm the role of LLM in improving dairy calf’s performance.

AN16268Relationship between the fatty acid composition of uropygial gland secretion and blood of meat chickens receiving different dietary fats

Khaled Kanakri, Beverly Muhlhausler, John Carragher, Robert Gibson, Reza Barekatain, Carolyn Dekoning, Kelly Drake and Robert Hughes

Determining the fatty acid status of chickens requires invasive methods to obtain blood samples for analysis. We postulated that measuring the fatty acid composition of preen oil, which is externally secreted from the uropygial gland of live chickens could be an alternative non-invasive method. However, the results showed that the fatty composition of preen oil is not a suitable indicator of the whole blood fatty acid profile in chickens.

The present study examined the effect of changes to the national inventory on the emission intensity of milk production of 41 Australian dairy farms previously assessed using the Dairy Greenhouse Gas Abatement Strategies calculator. The national mean emission intensity of milk production has increased, although individual farm emissions have either increased or decreased, depending on a range of factors. Methane from waste management has emerged a new ‘hot spot’, which will need consideration in terms of mitigation options moving forward.

AN15883Asparagopsis taxiformis decreases enteric methane production from sheep

Xixi Li, Hayley C. Norman, Robert D. Kinley, Michael Laurence, Matt Wilmot, Hannah Bender, Rocky de Nys and Nigel Tomkins

The marine alga Asparagopsis taxiformis has been shown to inhibit methane production in vitro. The present study compared the methane production from sheep offered increasing inclusion levels of Asparagopsis for 72 days. We found that a high-fibre pelleted diet supplemented with Asparagopsis resulted in up to 80% reduction in methane output compared with the same diet without Asparagopsis.

Heat stress is one of the major challenges for sustaining livestock production globally. Therefore, it is necessary to devise strategies for amelioration of heat stress by selecting genetically resilient animals for optimum productivity. The present study identified heat stress-tolerant and heat stress-susceptible individuals on the basis of heart rate and respiration rate. The selection method can be utilised for selecting animals towards improved resistance to heat stress and managing the livestock for better production and welfare.

Nitrate salts are recommended to reduce methane emissions in extensively grazed cattle. After treatment with nitrate salts for 7 days and walking 3 km Bos indicus steers demonstrated a reduction in the oxygen carrying capacity of their blood and an elevated heart rate. The recommended dose rate of nitrate salts to reduce methane emissions in cattle will create a hypoxaemia in cattle.

AN16018Genome-wide association studies, meta-analyses and derived gene network for meat quality and carcass traits in pigs

Darlene Ana S. Duarte, Marina Rufino S. Fortes, Marcio de Souza Duarte, Simone E. F. Guimarães, Lucas L. Verardo, Renata Veroneze, André Mauric F. Ribeiro, Paulo Sávio Lopes, Marcos Deon V. de Resende and Fabyano Fonseca e Silva

Genome association studies for meat quality and carcass traits have identified genes and markers of major relevance for modern pig breeding industries. We have validated significant markers for meat quality and carcass traits with meta-analysis. Further, we developed gene network from GWAS that identified key transcription factors, gene-gene interactions and molecular pathways contributing to understanding the molecular genetic mechanisms underlying these traits in pigs.

Medicago arborea and olive cake can be used in sheep diets as alternative feeds to reduce cost production and/or improve meat quality. Effects of olive-cake supplementation on meat quality of indoor and grazing lambs were studied. Grazing on rangeland containing Medicago arborea improved nutritional meat quality and stability of lipids. Olive cake supplementation did not have any effects.

The management of compost bedded systems aims to provide a clean and comfortable place for cows. However, unappropriated management can increase bedding moisture, which may reflect on cow’s health and milk quality. This study proposed to understand the relationship between bacterial populations on bedding pack and bacterial population found on teat end surface and in milk. In the end, we concluded that hygiene score was not an efficient tool to estimate bacterial population on teat end and milk.

AN16523Effects of aging on characteristics of breast meat from free-range broiler hens at 12 or 70 weeks of age

J. L. M. Mello, R. A. Souza, F. B. Ferrari, A. Giampietro-Ganeco, P. A. Souza and H. Borba

Little is known about the acceptability of free-range broiler hen meat. This study evaluated the effect of broiler age and the aging process on the properties of broiler hen breast meat. Its use is beneficial because it has lower storage and cooking losses and lower polyunsaturated fatty acid concentration, which makes it less vulnerable to rancidification. Aging for at least 3 days at 2°C is satisfactory to tenderise the breast meat from free-range broiler hens.

Hierarchical relationships between individuals of several ruminant species result in differential access to resources and thus in advantages in reproductive performance of those of higher social rank. Under captive conditions with high food availability as in the present experiment, reproductive traits of red deer females were unrelated to social rank. These results reaffirm the concept that most ruminants have plastic responses to environmental conditions, and thus, not necessarily social structure affects their reproductive performance.

AN16548Genetic evaluation of bodyweight, scrotal circumference, and visual appraisal scores in Bos indicus cattle

L. R. A. Abreu, L. F. M. Mota, T. A. Ferreira, I. G. Pereira, A. V. Pires, S. D. J. Villela, F. A. Merlo and P. G. M. A. Martins

Estimates of genetic parameters are broadly studied in Brazil for Bos indicus animals, particularly in Nellore cattle, but conversely, for Guzerat, another B. indicus breed, no studies were performed. A study was designed to estimate the genetic parameters and trends for body conformation measures. The magnitude of direct heritability estimates ranged from moderate to high, and genetic and phenotypic trends indicate favourable changes during the evaluated period.

The Campos region is the largest biogeographic unit of native grasslands in South America and cow-calf operations primarily graze this grassland. We studied the effects of herbage allowances of 2.5 (low) and 4 (high) kg dry matter/kg liveweight in primiparous beef cows over the entire production cycle on forage mass, cow body condition score, cow liveweight, stocking rate, postpartum anoestrus, probability of pregnancy and calf weight at weaning. The forage mass, reproductive and productive responses were improved in high herbage allowances over 2 years with different patterns of rainfall.

AN16570Determining the appropriate selection index for Rayeni Cashmere goat under pasture-based production system

Najmeh Kargar Borzi, Ahmad Ayatollahi Mehrgardi, Masood Asadi Fozi and Mahmood Vatankhah

Rayeni Cashmere goat is raised by nomads in Kerman province of Iran. Nomads have no guidelines to establish a breeding program in their herds. The aim of the current study was to investigate breeding goals and find the best selection index for Rayeni Cashmere goat. The most appropriate selection index for this breed was determined to improve nomad income by genetic improvement of Rayeni Cashmere goat epopulations.

AN15873Determinants of consumer willingness to pay for quality-graded Australian sheep meat

Kara Tighe, Oscar Cacho, Stuart Mounter, Renato Villano, Alex Ball, David Pethick and Euan Fleming

The present study investigated the influence of a quality-grading system, demographic information and consumption preferences on consumer willingness to pay (WTP) for sheep meat. Eating quality was defined by four grades developed by the Meat Standards Australia (MSA) sheep-meat grading scheme. Results clearly showed that consumers were willing to pay more for sheep meat as eating quality improved. Robust results for the impact of demographic and consumption preferences on WTP were limited to consumer age, occupation, income level and the interaction between MSA grade and consumer age.

AN16577Simple and robust algorithms to estimate liveweight in African smallholder cattle

J. P. Goopy, D. E. Pelster, A. Onyango, K. Marshall and M. Lukuyu

Liveweight (LW) is a key measurement for livestock owners but most farmers in sub-Saharan Africa have to use heart girth measurements to estimate LW because they cannot access scales. Most equations used to estimate LW are population specific and have large prediction errors, but using several large databases we developed an equation with less error, which can be used in a wider population. A stronger, widely applicable equation to estimate LW of African cattle will enable farmers to make better livestock management decisions.

Feeding distillers grains in beef feedlot diets decreases shelf-life, while supplementing antioxidants may mitigate such effects. This research evaluated the effects of feedlot diets containing distillers grains and different antioxidants on the shelf-life of retail-displayed beef. Results showed that supplementing feedlot cattle vitamin E alone or with a synthetic antioxidant was effective in shelf-life extension, which could provide long-range improvement in beef quality.

AN16694Using Walk-over-Weighing technology for parturition date determination in beef cattle

Don Menzies, Kym P. Patison, Nick J. Corbet and Dave L. Swain

Genetic selection can greatly increase fertility, which is a major profit driver in northern Australian beef enterprises, but to do so a cow’s calving date is required. Traditionally the calving date is recorded using laborious and costly methods, however, results show that the date can be automatically recorded using a remote weighing system. This will enable seedstock producers to more easily record the calving date, therefore, increasing the recording of fertility traits and consequently increasing the profitability of beef producers in northern Australia.

Chicken meat consumption has increased considerably worldwide due to its low fat content; however, it contains a high amount of polyunsaturated fatty acids that make it susceptible to oxidation. The source of lipids in poultry diets could affect carcass fat composition and increase the need for antioxidants. This study demonstrates higher lipid oxidation in stored meat of broilers fed soybean oil than canola oil in the diet. Dietary vitamin E supplementation reduced meat lipid oxidation; however, vitamin C was ineffective at preserving meat against oxidative damage.

AN16673An assessment of sire-breed effects on carcass and meat quality traits of lambs at the ages of 40 and 100 days from Comisana ewes crossed with Suffolk or Bergamasca rams

Pasquale De Palo, Aristide Maggiolino, Pasquale Centoducati, Giovanna Calzaretti, Edmondo Ceci and Alessandra Tateo

Lamb meat production is a worldwide phenomenon. Improving the production and profitability of sheep farms is an excellent way of guaranteeing their subsistence. Crossbreeding dairy ewes with meat rams enhances productivity without affecting meat quality.

The management of natural grasslands is crucial to increase meat production and ranchers profitability. This study aimed at assessing winter management of natural grasslands using sheep; continuous stocking and 12% herbage allowance improved sward quality in spring. These results provide an important management tool for grasslands ranchers so as to improve sward quality during spring.

AN16712Meta-analysis of genetic-parameter estimates for reproduction, growth and carcass traits in Nellore cattle by using a random-effects model

Hinayah Rojas de Oliveira, Henrique Torres Ventura, Edson Vinícius Costa, Mariana Alencar Pereira, Renata Veroneze, Marcio de Souza Duarte, Otávio Henrique Gomes Barbosa Dias de Siqueira and Fabyano Fonseca e Silva

Different studies have reported contradictory heritability and genetic-correlation estimates for reproduction, growth and carcass traits in purebred Nellore cattle. The motivation for the present study was to remove the heterogeneity between published estimates and summarise the results through meta-analysis using a random-effects model.

AN16801Sperm quality, and morphology and apoptosis of germinal epithelium cells of ram lambs receiving water of different salinities

T. L. B. G. Lins, V. G. Menezes, R. S. Barberino, S. A. P. Costa, N. M. S. S. Santos, T. V. C. Nascimento, M. A. A. Queiroz, M. F. Cordeiro, L. B. Ribeiro, G. G. L. Araujo and M. H. T. Matos

The ground water from semiarid areas has been an alternative source of drinking water for the small ruminants; however, it shows a wide variation in the concentration of total dissolved solids (i.e. salinity). Consequently, water salinity could affect apoptosis in testicular seminiferous tubules and, further, semen quality in ovine species, which was confirmed in the present study. Therefore, high-salinity water should be avoided because it increases the damage to the germinal cells of ram lambs.

Because of bad repercussions from using antibiotics and other chemical preparations, there was a dire need for natural alternatives. Our work aimed to investigate the impacts of using peanut skin powder on growth and health of broilers. Peanut skin powder lowered the amounts of carcass fats and minimised blood cholesterol, creatinine and urea, which means healthy chicken meat was gained.

AN16461Shearing ewes in the first third of gestation improves offspring performance

C. López-Mazz, F. Baldi, G. Quintans and G. Banchero

We investigated the effect of shearing at 50 days of gestation on ewes grazing in improved pastures, on the vigour of lambs at birth, liveweight at birth and weaning weight. Early shearing coincides with the timing of development and growth of the placenta. Early shearing positively improved birthweight and weaning weight of individual and twin lambs. The twin lambs were more vigorous, which improved the rate of survival at birth. Therefore, shearing at 50 days of gestation can become a useful tool for sheep farmers.

The present study examined the capacity of young male goats to tolerate high levels of salinity in drinking water without harmful effects to their physiology. It seems that goats are better adapted to sustain their lives and remain productive in regions where fresh drinking water is scarce and of high salt concentration, thus limiting the presence and productivity of other herbivores. Subsequently, this raises considerations on the sustainable management of these lands and the capacity of these regions to support a conventionally calculated number of livestock units (LU), irrespective of animal species used.

The effect of growth path to slaughter on the quality of beef from suckler bulls raised in a temperate grass-based production system has not been widely studied. This study has shown that increasing the growth of bulls during the winter, above that advised for steers, has no commercially relevant effect on the sensory characteristics of beef. Producers therefore can economically optimise the growth path of bulls without concern for a deleterious effect on beef quality.

AN16603A comparison of the effects of post-mortem aging on breast meat from Cobb 500 and Hubbard ISA broilers

J. L. M. Mello, R. A. Souza, G. C. Paschoalin, F. B. Ferrari, B. M. Machado, A. Giampietro-Ganeco, P. A. Souza and H. Borba

This study compared the characteristics of the breast meat from Cobb 500 and Hubbard ISA broilers and evaluated the effect of aging for up to 7 days on meat quality. Even though meat from Hubbard ISA broilers is less tender, its use may be beneficial to the poultry industry due to the lower production of exudate. Moreover, it has higher levels of PUFA, which is beneficial to human health. Aging for 3 days at 2°C is sufficient to tenderise and add value to free-range meat.

Fermenation and aerobic stability is an important issue for total mixed ration (TMR) silage because of its low moisture and high nutrition. This study improved fermentation quality and aerobic stability of TMR silages by the combination of L. plantarum and ethanol. The result could provide a theoretical basis for selection of additive in TMR silage.

Low rates of feed additive can improve poultry production and excreta characteristics. Biochar, zeolite and bentonite added to layer poultry rations at low rates resulted in improved feed conversion rates, especially when birds were challenged with fungus contaminated feed. These results may reflect an impact of these feed amendments on gut ‘health’ (microbiology or absorption of feed toxins).

This study demonstrates that sheep and beef enterprises can reduce or entirely offset their greenhouse gas emissions by storing carbon in trees. The carbon balance was calculated for enterprises with different stocking rates and levels of tree cover, and an intensively stocked case study farm was also analysed. Most stocking rates were carbon positive with >20% tree cover. This study provides an important reference point for farmers, researchers and policy analysts to estimate the carbon balance of farms.

As is known to all, milk has a great influence on our health, so we should pay attention to the feeding and management of dairy cows. The present study indicated that the novel carbohydrate balance index, ‘CBI’, may regulate the growth and development of cows. In future work, the CBI level may be applied in feed formulation for dairy cows.

Housing and feeding systems affects the fattening and slaughter parameters of finishing pigs with different genotypes. Considering the selection of appropriate production technology of finishers should be well recognised for each solution. The best results in a study population were achieved for four-ways crossbreeding finishers on slatted floors and fed by liquid feeding.

AN16540Impact of dietary Moringa oleifera leaves on intestinal pathogenic load and histological structure of growing rabbits raised under heat-stress conditions

A. Y. El-Badawi, I. El-Wardany, S. I. Abd El-Moez, F. I. S. Helal, Nematallah G. M. Ali, M. I. Shourrap and O. M. Aboelazab

Heat stress is a major problem for rabbits, which causes negative effects on the animal’s health that can extend to death. Natural antioxidants, such as moringa leaves, could be used as a dietary growth promoter for rabbits, helping to face problems induced by heat stress. The improvement of rabbits’ intestinal health encourages researchers to discover the other beneficial impacts of moringa leaves.

In recent years, restricting or prohibiting the addition of antimicrobial substances in diets has led to investigation into the use of plant extracts as feed additives. Therefore, the objectives of this study were to determine the effects of aromatic oregano (Oreganum onite L.) water on performance, immune system and general health of Holstein calves. The results of this study show that the natural additive of aromatic oregano water could be used successfully and safely in milk replacer to improve the overall performance of calves.

The combination of a live vaccine into an inactivated vaccine provides convenience to poultry farmers in administration. This study evaluated the survival and effectiveness of the live vaccine when administered this way. The live vaccine had reduced viability over time and the birds showed a reduced immune response to it when adminsitered this way.

Crossbreeding is one of the main strategies to improve the meat quality of different dry-cured meat products. It is well known that lean/fat ratio and fat deposition in pigs is largely conditioned by the pig breed employed. In this study, hams obtained from crossbreeding pigs presented higher intramuscular fat than pure line hams. This is a positive point because intramuscular fat affect the juiciness and tenderness. As a general conclusion, the crossbreeding of Celta pigs allows us to improve the quality of dry-cured hams.

In animal production, herbal medicines that have already been tested in alternative human medicine are commonly used. This study demonstrated that a 2% and 2.5% addition of the Boswellia serrata resin in the diets can be used to improve haematological and biochemical blood parameters and receive good quality carcass. However, no clear impact of Boswellia serrata resin on humoral immunity was found. The Boswellia serrata resin can be efficiently used in chicken diets as a phytobiotic.

AN16747Impact of zilpaterol hydrochloride and soybean-oil supplementation on intramuscular fat, fatty acid profile and cholesterol concentration in the longissimus muscle of male hair lamb under moderate heat-stress conditions

J. L. Dávila-Ramírez, L. Avendaño-Reyes, E. A. Peña-Ramos, T. Y. Islava-Lagarda, U. Macías-Cruz, N. G. Torrentera-Olivera, R. Rojo-Rubio and H. González-Ríos

Zilpaterol and soybean-oil effects on lipid composition of lamb meat were studied under moderate heat-stress conditions. From a human nutrition standpoint, meat lipid composition was not improved by using zilpaterol and soybean oil. New strategies to nutritionally improve the lamb meat lipid profile should be explored.

AN16437Endoparasite and nutritional status of Suffolk lambs in seven production systems

Jordana Andrioli Salgado, Marcelo Beltrão Molento, Cristina Santos Sotomaior, Laila Talarico Dias, Luciana Laitano Dias de Castro, Laura Derenevicz Faisca and Alda Lúcia Gomes Monteiro

Endoparasite and nutritional statuses of Suffolk lambs were compared across a range of production systems in subtropical conditions of Brazil. The weaned-feedlot lambs and those in the controlled-suckling systems presented the best performance, and the animals in creep-feeding and creep-grazing had the best overall performance on pasture. Production systems exert a major influence on lamb performance, mainly when the ewe is present and supplementation is given on pasture. Nutritional status in different production systems may support overcoming the challenge caused by gastrointestinal nematodes.

The administration of equine chorionic gonadotropin (eCG) or gonadotropin-releasing hormone (GnRH) during the luteal phase promote serum progesterone concentrations in ewes. We evaluate pregnancy rate obtained with eCG and/or GnRH treatment after FTAI. The eCG administration on Day 10 after FTAI had a marginal positive effect on pregnancy establishment during the first month, which was not maintained during the second month of gestation. No effect of GnRH treatment on Day 6 and 11 was found.

AN16745Energy relations in cattle can be quantified using open-circuit gas-quantification systems

M. Caetano, M. J. Wilkes, W. S. Pitchford, S. J. Lee and P. I. Hynd

Current methods for estimating energy intake and expenditure of ruminants in the field have a range of technical problems. The open-circuit gas-quantification system (GQS) provides a simple, alternative means of quantifying energy intake and expenditure in the field. The potential for GQS to estimate intake represents an important potential breakthrough for identifying and selecting cows with greater feed efficiency in grazing systems.

AN16288Production responses in young bulls fed glycerin as a replacement for concentrates in feedlot diets

A. C. B. de. Barros, J. N. M. Neiva, J. Restle, R. L. Missio, F. R. C. Miotto, D. A. G. Elejalde and R. P. Maciel

To meet global demand, increases in meat production are essential. Although conventional feed costs may limit the feedlot finishing of beef cattle, this can be circumvented by the use of agro-industrial by-products. The use of crude glycerin in cattle diets can increase animal performance and reduce the cost of feeding.

AN16422Litter size at lambing influences genetic evaluation of maternal rearing ability

Kim L. Bunter, Andrew A. Swan, Daniel J. Brown, Forbes D. Brien and Jennifer Smith

Lamb mortality is an important production and welfare issue worldwide. In this paper we demonstrate how litter size affects the maternal genetic contribution to lamb survival and compare alternative approaches to defining the ewe rearing ability trait, ignoring or accommodating variation in lamb survival due to litter size. The accuracy of genetic evaluation for rearing ability may be improved if the impact of litter size on lamb mortality is considered.

Estimation of microbial fermentation of concentrate feeds for ruminants from the in vitro gas-production technique is biased by the differences in incubation pH, established at ~6.5 when rumen pH actually drops below 6.0 in this type of diets. Adjustment of incubation pH by reducing the buffering of the medium is a simple way to overcome this problem in short-length incubations.

AN16582Growth and reproductive traits of F1-generation transgenic goats for human granulocyte-colony stimulating factor

R. I. T. P. Batista, J. M. G. Souza-Fabjan, D. Í. A. Teixeira, L. M. Melo and V. J. F. Freitas

The randomness of transgene insertion in genetically modified animals by the microinjection technique may compromise the health and welfare of animals. We demonstrate in this work that insertion of the human granulocyte-colony stimulating factor (hG-CSF) transgene in the two lines of transgenic goats does not compromise the health of animals. This information is an important step in the use of animals as bioreactors for the production of large-scale hG-CSF.

AN16161The use of energy-protein supplement increases performance of high-yielding dairy cows and improves health-promoting properties of milk

Anna Malgorzata Brzozowska, Piotr Micek, Beata Kuczynska, Marek Lukaszewicz and Jolanta M. Oprzadek

We can increase the content of milk components desirable from the human health point of view by feeding lipid additives to cows. The aim of the study was to determine the effects of a special supplement on health-promoting properties of milk. We discovered that the supplement had a beneficial effect on milk properties, and produced milk that may serve the role of functional food for people in the future.

AN15306Consumer acceptability of beef from two sexes supplemented with essential oil mix

A. Guerrero, D. C. Rivaroli, C. Sañudo, M. M. Campo, M. V. Valero, A. M. Jorge and I. N. Prado

Essential oils have many possibilities as feed additives in livestock as natural alternatives to replace other chemical additives. Consumer acceptability of meat from these types of natural additives is important in order to increase the knowledge about these promising feeding systems. Essential oil additives in the diet of crossbred beef cattle did not negatively affect consumer meat acceptability scores or product perception.

AN16440Quantifying dairy farm nutrient fluxes and balances for improved assessment of environmental performance

Innocent Rugoho, Hayden Lewis, Muhammad Islam, Andrew McAllister, Gemma Heemskerk, Andrew Gourley and Cameron Gourley

Excess nutrients are challenging the long-term sustainability of grazing-based dairy farming. We have developed an online tool that quantifies nutrient fluxes, balances and efficiency, as well as feed and milk production performance at the whole-farm level. This standardised assessment provides dairy farmers, advisors and industry and policy analysts with the ability to improve environmental performance and develop industry-wide goals.

This study completed a life cycle assessment of energy, water and land occupation from pork production, covering supply chains and the national herd. Impacts arose predominantly from feed production, highlighting the importance of system efficiency, and particularly the feed conversion ratio for reducing resource use and environmental impacts. Changes to housing and improvements to manure management offer substantial opportunities for reducing the resource use intensity of pork.

AN16616Using ultrasound to derive new reproductive traits in tropical beef breeds: implications for genetic evaluation

N. J. Corbet, J. M. Allen, A. R. Laing, G. Fordyce, M. R. McGowan and B. M. Burns

Ultrasound has enabled the identification of heifers genetically superior for the ability to reach sexual maturity and become pregnant earlier in the breeding season, attributes that profoundly impact lifetime reproduction. Research methods to identify superior individuals have laboriously involved multiple ultrasound examinations, so the current research adopted previous methodology to enable identification of superior breeding females using a single ultrasound examination. Adoption of ultrasound technology by commercial beef producers to measure fertility in their herds will be enhanced if a simple, robust system is presented.

AN16687Influence of low-protein and low-amino acid diets with different sources of protease on performance, carcasses and nitrogen retention of broiler chickens

Z. U. Rehman, J. Kamran, M. E. Abd El-Hack, M. Alagawany, S. A. Bhatti, G. Ahmad, A. Saleem, Z. Ullah, R. M. K. Yameen and C. Ding

There are some nutritional strategies that can be used to improve poultry performance and public health like supplementation of commercial enzymes to low-protein diets. The aims of this study were to evaluate the impacts of commercial enzymes supplemented into low-protein diets on performance and economic aspects of broilers. Using different commercial enzymes in low-density diets can partially improve performance and economic aspects in broilers.

AN17141Aspects of digestive function in sheep related to phenotypic variation in methane emissions

J. J. Bond, M. Cameron, A. J. Donaldson, K. L. Austin, S. Harden, D. L. Robinson and V. H. Oddy

Ruminant livestock production results in methane (CH4) emissions, a greenhouse gas. The present research focussed on aspects of the host animal’s biology that influence between sheep variation in CH4 emissions. Dry matter intake, liveweight, reticulo-rumen volume, the proportion of contents in the rumen compartments and digesta flow rate were important factors. Our expanded understanding of the host’s control of CH4 emissions will inform the development of procedures to mitigate CH4 production from sheep and improve ruminant nutrition.

Comprehensive understanding of the effect of pig breed and sex on meat quality and post-mortem muscle conditions will be necessary to estimate post-mortem meat quality. Here, we applied multiple regression and principal component analysis on multiple breeds and sexes. We observed that muscle pH, lightness, and drip loss are useful for estimating ultimate pork quality.

AN17466Efficiency of mating, artificial insemination or resynchronisation at different times after first timed artificial insemination in postpartum Nellore cows to produce crossbred calves

Walvonvitis Baes Rodrigues, Jean do Prado Jara, Juliana Correa Borges, Luiz Orcirio Fialho de Oliveira, Urbano Pinto Gomes de Abreu, Natalia Albanese Anache, Karine Casanova da Silva, Alexandre de Oliveira Bezerra, Christopher Junior Tavares Cardoso and Eriklis Nogueira

Artificial insemination is a tool to produce calves with improved performance in extensive management systems. This trial evaluated different post-timed artificial insemination (AI) managements, and shows that resynchronisation programs of 22 or 30 days are more efficient to produce AI products, and final pregnancy is similar among the treatments, differing only in the amount of calves produced by AI.

Omega-3 and omega-6 fatty acids are considered to be nutritionally essential but cannot be synthesised by humans and animals. The balance of these two fatty acids is important for health and longevity rather than the absolute amount, therefore this study focused on evaluating the dietary supplementation of varying ratios of omega-6 : omega-3 fatty acids (15 : 1, 10 : 1 and 5 : 1) on the performance, nutrient digestibility, immune status and faecal microbiota of weaner pigs. As a result of this study, the reduction of the omega-6 : omega-3 fatty acid ratio from 15 : 1 to 5 : 1 in the diet showed a positive effect on the growth performance of pigs during phases 1 and 2; dry matter, nitrogen and energy digestibility and HDL cholesterol concentration increased linearly during week 3 but no effect on faecal microbiota were observed with the reduction of the omega-6 : omega-3 FA ratio from 15 : 1 to 5 : 1, indicating that the ratio of 5 : 1 is beneficial to weaner pigs.

AN16512Sheep and goat browsing a tropical deciduous forest during the rainy season: why does similar plant species consumption result in different nutrient intake?

J. Ventura-Cordero, P. G. González-Pech, J. F. J. Torres-Acosta, C. A. Sandoval-Castro and J. Tun-Garrido

The vegetation of tropical deciduous forests represent an important source of nutrients for small ruminants in many farms; however, feeding behaviour and nutrient intake of sheep and goats in that vegetation during the rainy season is unknown. We showed that both consumed similar plant species but had different feeding behaviour, goats browsed more than sheep, obtaining more protein and polyphenols. Sheep and goats consumed an imbalanced diet that would require dietary energy for goats and a protein : energy supplement for sheep.

AN16641Neurophysiological development of newborn pigs: effect of the sow

P. Roldan-Santiago, D. Mota-Rojas, J. Martínez-Burnes, A. Velarde, R. Muns and A. López-Mayagoitia

The present study demonstrated alterations in the health of newborn piglets and low vitality scores were due to the effects of the parity of the sow. The objective was to determine the effect of sow parity on neonatal piglet health and vitality at birth. Results suggest that not only births classified as distocic affect the physiological responses of newborn piglets.

AN16563Genetic association between stayability, and productive and reproductive traits in Holstein cows

Graziela M. F. Rocha, Jaime A. Cobuci, Cláudio N. Costa, Luíza R. A. Abreu, Lúcio F. M. Mota, Aldrin V. Pires, Severino D. J. Villela and Paulo G. M. A. Martins

An important trait is the length of the productive life of a cow in the herd, or stayability. Here we estimate genetic merit of Brazilian Holstein cows and correlations of stayability with other measures of performance. We show low heritabilities for stayability but positive genetic correlations with milk production, suggesting that animals can be selected for both stayability and milk production in this population.

The interest in improving periparturient health through dietary supplements has received great attention in recent years. The purpose of this study was to compare the effects of niacin, choline and cod liver oil on metabolic variables, and indices of insulin sensitivity in cows with subclinical ketosis. The findings of this study suggest benefits of prepartum supplementation to cattle with subclinical ketosis and could support the advancement of future investigations in animal production.

Consumption of lamb meat has decreased considerably, in addition to preference for first class pieces only. In order to increase carcass value and consumption, lamb burgers were prepared from different parts of the carcass and spices. The results showed that the manufacture of these meat products could optimise the value of lamb carcass.

AN16530Mineral status of reproducing ewes grazing vegetative cereal crops

David G. Masters, Serina Hancock, Gordon Refshauge, Susan Robertson, Marie Bhanugopan, Michael Friend and Andrew N. Thompson

Many producers avoid grazing vegetative cereal crops with reproducing ewes because of a suspected risk of metabolic disease. Monitoring of the mineral status of wheat, oats and barley, and of the pregnant ewes grazing these crops indicated an imbalanced mineral supply from crops and consequent low mineral status of ewes on some farms. Strategies to minimise the risk of hypocalcaemia and hypomagnesaemia are required.

AN17003Effects of phosphorus supplementation in high-grain diets on blood, chemical and physical parameters of bones of feedlot Nellore bulls

Vinícius C. Souza, Pedro Malafaia, Yury T. Granja-Salcedo, Bruno R. Vieira, Raphael S. Gomes, Diogo F. A. Costa, João Alberto Negrão, Antônio C. Shimano and Telma T. Berchielli

Bone growth is directly correlated to mineral nutrition, with emphasis on phosphorus (P) under Brazilians conditions. We evaluated the effect of P supplementation in high-grain diets on blood, chemical and physical parameters of bones of feedlot Nellore bulls. P concentration of 2.4 g/kg in DM was adequate to ensure health and its supplementation resulted in no benefits in neither chemical nor physical properties from bones of feedlot Nellore cattle, with emphasis for the increase of pollution and economic losses in Brazilian feedlots.

AN16388Feed resource selection by Criollo goats browsing a tropical deciduous forest

J. Ventura-Cordero, P. G. González-Pech, C. A. Sandoval-Castro, J. F. J. Torres-Acosta and J. Tun-Garrido

Plants of the tropical deciduous forest (TDF) represent a valuable feed resource for goats in hot sub-humid environments, but little is known about the goats’ feeding behaviour in the TDF. Sustainable use of TDF by browsing goats requires establishing whether plant resources will be consumed in proportion to their availability or whether particular plant species are actively selected or refused. This study showed that goats consumed several plant species, while actively selected only a few plants, and such behaviour changed in different browsing sites. This information could assist with the development of management strategies leading to protect the valuable plant resources of the TDF by goats.

The fermentation pattern of varieties of cereal grains (sorghum, maize and barley) depending on the nature of the rumen microbial population has been studied in vitro, simulating high-concentrate conditions by modifying the incubation pH, improving the conventional approach. Concentrate inoculum promotes a higher fermentation of starch substrates than that induced by a forage diet, at a higher extent with vitreous starch sources. Differences among varieties for each cereal species suggest the need for care in the extrapolation of results.

Zinc is crucial for a wide variety of physiological processes in all animals. The aim of this experiment was to assess the levels and zinc sources effect on broiler chicken performance. Results demonstrated that supplementation diet with 50 mg of organic Zinc may be sufficient for normal broiler growth to 28 days of age.

AN15375Supplementation of dairy cows with commercial concentrate or ground maize grain under cut-and-carry or grazing of cultivated pastures in small-scale systems in the highlands of central Mexico

J. Velarde-Guillén, J. G. Estrada-Flores, A. A. Rayas-Amor, F. Vicente, A. Martínez-Fernández, D. Heredia-Nava, M. D. Celis-Alvarez, I. K. Aguirre-Ugarte, E. Galindo-González and C. M. Arriaga-Jordán

Small-scale dairy systems are a development option to ameliorate rural poverty, but in Mexico they have high feeding costs due to reliance on external inputs. This work shows that ryegrass/white clover pastures under grazing may meet protein requirements of lactating dairy cows for moderate milk yields with similar feeding costs than cut-and-carry pasture but with less effort and; and full replacement of commercial concentrate by locally produced maize grain in the diet can maintain milk yield and milk composition of dairy cows grazing pasture under small-scale dairy systems in Mexico.

A large proportion of the ammonia deposited by feedlots cattle is lost as gaseous ammonia and may subsequently be vulnerable to a greenhouse gas. This ammonia loss was measured (~60% of excreted N), while simultaneously measuring deposition to the area surrounding the feedlot (2–3% deposited within 600 m). Two implications are evident: (1) standard greenhouse gas inventory calculations tend to underestimate the gaseous loss of ammonia from beef feedlots; and (2) most of this ammonia is probably diluted and ultimately deposited in the wider landscape.

AN17104The effects of dry or wet aging on the quality of the longissimus muscle from 4-year-old Hanwoo cows and 28-month-old Hanwoo steers

Jungmin Oh, Hyun Jung Lee, Hyun Choel Kim, Hyun Joo Kim, Yeong Gwon Yun, Kwan Tae Kim, Yang Il Choi and Cheorun Jo

Beef from Hanwoo cows is known to be of poor quality because most cows are old (>40 months old) and have produced several calves before slaughter. Meat aging is used to enhance meat quality, regardless of the method employed. This study demonstrates that meat quality from 4-year-old cows is enhanced by 28 days of dry or wet aging to yield meat of quality similar to that of much younger steers.

Horse meat has become more popular and is considered as a new alternative in meat consumption. The study was conducted as a part of the routine slaughtering practice and post mortem processing of horse meat in the specialised commercial butchery. Among the numerous factors that can influence horse meat quality, the most important ones are age at slaughter and muscle type; these factors must be considered in the routine slaughtering practice and in further research.

AN17065Serological diversity, molecular characterisation and antimicrobial sensitivity of avian pathogenic Escherichia coli (APEC) isolates from broiler chickens in Kashmir, India

S. N. Magray, S. A. Wani, Z. A. Kashoo, M. A. Bhat, S. Adil, S. Farooq, M. A. Rather, Z. A. Kabli, M. T. Banday and Y. Nishikawa

Avian colibacillosis caused by avian pathogenic Escherichia coli (APEC) is responsible for heavy economic losses to commercial broiler farmers. The present work investigated APEC isolates and their comparison with avian faecal E. coli (AFEC) isolates. The results suggest that virulence genes were more prevalent in APEC than in AFEC and the majority of the APEC isolates exhibited a multi drug resistant pattern. The present study will serve as a reference study for future work on APEC and extra intestinal pathogenic E. coli.

Under- or over-stimulation of the immune system is detrimental to pig health and productivity. The complexity associated with the immune system, factors influencing its activation, and the subsequent impacts on animal metabolism, are reviewed. Potential management strategies are suggested for optimising the immune response for pigs reared in any specific environment.

AN16752Commercial equine production in New Zealand. 2. Growth and development of the equine athlete

Chris W. Rogers, Erica K. Gee, Charlotte F. Bolwell and Sarah M. Rosanowski

The utilisation of pasture as a predominant source of nutrition for broodmares and young stock is a unique feature of the New Zealand commercial equine industry. The export focus of the Thoroughbred industry has a large influence on many husbandry practices and industry structure.

The data in the present study are of practical importance to effectively take advantage of local forage recourses to produce feeds for dairy cows on the Tibetan Plateau. The use of propionic acid and lactic acid bacteria inoculants together could improve the fermentation quality, aerobic stability and in vitro dry matter digestibility of total mixed ration silage. Further research is needed to explore how the total mixed ration silages affect animal performance.

Enhanced near-infrared spectroscopy calibrations for the measurement of reactive lysine and digestible energy in feed ingredients for pigs represents a major advance in our capacity to define nutritional quality of ingredients prior to diet formulation. This paper outlines a robust calibration development process and presents advanced correlation analysis that can be used to investigate calibration outliers. Overall application will contribute to more efficient and sustainable pork production systems.

AN17192The sex ratio of a gilt’s birth litter can affect her fitness as a breeding female

J. Seyfang, R. N. Kirkwood, A. J. Tilbrook and C. R. Ralph

The breeding capacity of female pigs may be affected by male littermates in utero. This literature review covers the known effects of masculinisation of female rodents and sheep, as well as the knowledge gaps in pigs. The findings suggest that the effect of the birth litter sex ratio of a gilt on her suitability for breeding should be investigated further.

AN17052Application of accelerometers to record drinking behaviour of beef cattle

Lauren R. Williams, Greg J. Bishop-Hurley, Angela E. Anderson and Dave L. Swain

The amount of water cattle consume and the frequency that cattle drink affects their productivity, but a practical and inexpensive method to record drinking behaviour does not exist. The results of this study show that although further development of a classification method is required, accelerometers can record beef cattle drinking behaviour. This brings us closer to collecting information critical to understanding cattle drinking behaviour and ensuring that the amount and frequency of water consumption is sufficient to meet their needs.

AN16571Shade access in combination with sprinkling and ventilation effects performance of Holstein cows in early and late lactation

Lorena Román, Celmira Saravia, Laura Astigarraga, Oscar Bentancur and Alejandro La Manna

Depending on the stage of lactation, heat stress diminishes milk production in dairy cows differently. Two lactations stages (12 and 201 days in milk) and three mitigation strategies (none, only shade and shade combined with sprinkling and ventilation) were evaluated. Animal productivity was more negatively affected in early lactation, although mitigation strategies were effective to reduced heat stress effects on both stages of lactation.

AN16829Effects of maternal parity on the pork quality traits of progeny

Jun-Mo Kim, Dong-Geun Kang, Sang-Hoon Lee, Kyung-Bo Ko and Youn-Chul Ryu

Growth, health and production performances of progeny can differ depending on their maternal environment such as sow parity number. This study aimed to identify the influence of sow parity on the meat quality of progeny. We identified that maternal parity may affect pork quality in progeny and the younger stage group could have better meat quality than the older group.

AN16332Adding a bio-response modifier and zinc oxide to piglet weaner diets influences immunological responses to weaning

Ujjwal Kumar De, Reena Mukherjee, Chandan Prakash, Bhimnere Hanumanthagouda Manjunatha Patel, Sukdeb Nandi, Umesh Dimri, Ashok Kumar Verma and Med Ram Verma

The early weaning in pig husbandry has a tremendous impact on health condition and performance of piglets at the post-weaning period. The early weaning piglets are vulnerable to health ailments such as post-weaning scours and impaired immune response. Supplementation of BRM and ZnO in basal diet restored the important functions of neutrophils and reduced the inflammatory cytokine response. The important findings would help devise the strategies for effective and efficient management of early weanling piglets in farm conditions.

AN16434Agroforestry for ruminants: a review of trees and shrubs as fodder in silvopastoral temperate and tropical production systems

Sophie Vandermeulen, Carlos Alberto Ramírez-Restrepo, Yves Beckers, Hugues Claessens and Jérôme Bindelle

In any environment, appropriate plant–animal interactions are essential to achieve sustainable livestock intensification, food and nutritional security and improved livelihoods of farming communities. This study reviews grazing and browsing research to understand contrasting ruminant-agricultural practices to provide a solid foundation for developing sustainable farming practices. The outcome differentiates livestock feeding strategies and their impact on land-feed-use efficiency.

The supplementation with fibrolytic enzymes (FE) could compensate for the inadequate endogenous enzymes in calves, increase feed fibre degradability and provide sufficient nutrients for ruminal bacteria which were promoted by isobutyrate (IB) supplementation. The combination of IB and FE has the potential to stimulate the growth of dairy calves during pre- and post-weaned period by increasing microbial enzyme activity and promoting the growth of cellulolytic bacteria.

AN16706Dietary zinc supplementation and the performance and behaviour of caged laying hens

Zahra Sorosh, Somayyeh Salari, Mohsen Sari, Jamal Fayazi and Saleh Tabatabaei

The behaviour of birds can affect their performance parameters and laying hens’ behaviour can be affected by nutritional factors such as zinc. The aim of the present study was to evaluate the effect of zinc on performance and behavioral parameters of laying hens. The results showed that zinc can improve laying performance and can decrease aggressive behaviour.

Common purslane is well known for its antioxidant and antilipogenic properties. This study compared the effects of dietary supplementation of herb powder, aqueous and methanolic extracts of this medicinal plant on growth performance, lipid metabolism and oxidative status of the plasma, liver and jejunum in broilers. The findings revealed that herb powder was the most suitable source of purslane, as its supplementation not only improved antioxidant status and plasma lipid levels, but also was associated with increased growth rate and decreased abdominal fat.

AN17487Efficiency of pea seeds in sow, piglet and fattener feeding

E. Hanczakowska, J. Księżak and M. Świątkiewicz

Legumes, among them pea, can be cultivated in cool-climate zones, are the main source of protein in human and farm animal nutrition. Unfortunately, legume seeds contain substances that limit their utilisation especially in young, most delicate animals; therefore, in this experiment, the possibility of using new varieties of pea in sow, piglet and growing-pig nutrition was evaluated. Results pointed to the possibility of using cheap on-site produced protein in the whole cycle of pig feeding.

AN17070Carcass lean-yield effects on the fatty acid and amino acid composition of Duroc pork and its technological quality after vacuum-aging

J. Álvarez-Rodríguez, R. Ros-Freixedes, S. Gol, E. Henríquez-Rodríguez, R. N. Pena, L. Bosch, J. Estany, F. Vilaró and M. Tor

Carry-over effects on chemical composition of raw pork and technological meat quality after vacuum ageing up to 4, 6 and 8 days may be observed due to carcass grading based on lean content. Meat fatness did not affect its amino acid balance and technological quality (colour, drip loss, shear force and lipid stability), but modified intramuscular fat composition.

This study explored the potential for producers to breed for improved survival rates in Australian Merino sheep during the post-weaning period and reported the survival trait to be lowly heritable. Unfavourable genetic correlations with key production traits mean that selection based on popular MERINOSELECT indexes is leading to a very small reduction in the survival rate of lambs after weaning. To prevent a decline in survival, producers are advised to record weaner survival and include it in their breeding objective.

AN17289Protein dietary efficiency and methane emission in cattle fed soybean meal treated with tannins

R. Mezzomo, P. V. R. Paulino, M. M. Barbosa, T. S. Martins, L. G. R. Pereira, J. C. Silva, M. F. Paulino, M. C. Silva and N. V. Serão

Tannins provide an increase in the amount of protein used by the animal with no increase in the total amount of dietary protein. This occurs due to the capacity of tannin to bind protein through hydrogen bonds forming a tannin–protein complex, which is stable in the rumen (pH, 5.0–7.0) and resistant to microbial degradation. This approach can provide two important benefits: an increase in the amount of protein absorbed and deposited in the animal’s tissue and a decrease in feed costs due to the removal of protein source ingredients, such as soybean meal.

Can growth and carcass traits be enhanced in prime lambs using omega-3 oil supplements? Crossbreds had better carcass weight, dressing percentage and fat depth than purebred Merinos. Prime lamb producers can better match genetics with feed resources by supplementing first-cross lambs with pellets containing 5% canola oil or 5% flaxseed oil pellets in an intensive finishing period of 10 weeks.

During summer, heat stress often causes sow reproductive failure. In later pregnancy and lactation, sows are under multiple heat stress; dietary supplementation with N-carbamylglutamate and vitamin C can improve reproductive performance of sows by increasing litter and average weights at farrowing and weanning. Our results can be used to ameliorate heat stress in summer and keep year-round pig production.

AN16721Nutritional parameters of beef heifers fed diets with different roughages

K. A. K. de Moraes, E. H. B. K. de Moraes, D. S. Pina and S. C. Valadares Filho

Addition of calcium oxide (CaO) can improve the intake and digestibility of sugarcane silage in beef cattle. The objective of this study was to examine the nutritional parameters of feedlot beef heifers fed with corn silage, fresh sugarcane or ensiled sugarcane with different CaO levels. Corn silages diets provide better nutritional parameters than sugarcane diets. Adding CaO to sugarcane silage provides greater intake than silage without CaO. However, the use of high levels of CaO decreases the diet intake.

AN17215Modelling the egg components and internal cycle length of laying hens

H. C. P. Bendezu, N. K. Sakomura, E. B. Malheiros, R. M. Gous, N. T. Ferreira and J. B. K. Fernandes

With an accurate description of potential egg production, egg weight and its internal constituents (albumen, yolk, and shell), a simulation model to predict egg production and egg weight can be performed. Equations were developed to update the commercial layer genetic potential. This approach allows both improvement in egg production prediction and understanding of hen nutritional requirements.

AN16823Effects of hydrated sodium calcium aluminosilicate on growth performance, fatty liver, intestine morphology, and serum parameters of overfed geese

Junwang Tang, Maxue Lu, Qianqian Fang, Feizhen Lu, Rongyi Shao, Junda Shen, Dailin Lu, Jun He, Lizhi Lu and Dong Niu

As a worldwide-known delicacy, fatty goose liver (foie gras) is obtained from overfed geese; however, two factors could affect its safety and quality, excessive amounts of diet and antibiotics in feed. To solve this problem, we added hydrated sodium calcium aluminosilicate (HSCAS) into the diet and the results showed that HSCAS increased relative liver weight, serum immunoglobulin levels, and improved intestine morphology of overfed geese. HSCAS might serve as an alternative to increase nutrient absorption and replace antibiotics in foie gras production.

AN17055Recombinant bovine somatotropin on heifer’s biometric measures, bodyweight, blood metabolites, and dry matter intake predictions

Jefferson R. Gandra, Euclides R. Oliveira, Caio S. Takiya, Tiago A. Del Valle, Erika R. S. Gandra, Rafael Henrique T. B. Goes, Natyaro D. Orbach and Gessica Cristina G. Rodrigues

Strategies to accelerate growth of heifers decrease time until the productive period. This study evaluated whether sustained-release recombinant bovine somatotropin injections increase the growth rate of replacement dairy heifers. Recombinant bovine somatotropin increased bodyweight gain and skeletal growth, suggesting that heifers would reach puberty and productive life earlier, decreasing the energy waste related to methane and urine outputs into the environment.

AN17269Histomorphometric analysis of the small intestine of broiler chick embryos injected in ovo with methionine

Mohammad Naser Nazem, Sayed Mohsen Sajjadian, Reza Kheirandish and Hamideh Mohammadrezaei

The present study evaluated the histomorphometric effect on the small intestine of the chicken embryo after in ovo methionine injection. The results indicated that injecting methionine into the yolk sac can improve intestinal histomorphometrical parameters and that 40-mg methionine injection showed the greatest changes.

Lamb survival in Merino ewes, especially those bearing twins, can be very low leading to reduced production and animal-welfare concerns. The present study investigated whether providing barley grain in late gestation can improve lamb survival when pasture availability is high. Supplementation did not increase lamb survival and is not a recommended strategy where ample quality pasture is available throughout lambing.

Pig production is a common activity of smallholder farmers in Lao PDR but its degree of sophistication is low, leading to missed opportunities in generating income. We found a lack of understanding for focussed production reflected in village pig herd dynamics, underlining problematic management practices that lead to high losses and poor performance. Future development interventions are encouraged to take the indicated reasons for such practices into consideration to improve their chances of sustainable impact.

AN15624Herbal additives influence in vitro fermentative attributes and methanogenesis differently in cattle and buffalo

Ashok Kumar Pattanaik, Santosh Laxmanrao Ingale, Shalini Baliyan, Narayan Dutta, Devki Nandan Kamra and Kusumakar Sharma

Six different herbal additives were evaluated in vitro using rumen liquor inoculum sourced from cattle and buffalo. The herbal additives influenced differently the in vitro ruminal microbial production efficiency and methane-inhibitory attributes. Further, the response of the herbal additives was different when incubated in rumen inoculum from cattle versus buffalo, indicating the importance of the species of the donor animal for such in vitro studies. Additionally, this may have significant implications in practical feeding situations targeting methane-reduction strategies.

AN16550Dietary supplementation with glucogenic precusors and fatty acids improves performance and health of periparturient dairy cows

R. Klebaniuk, G. Kochman, E. Kowalczuk-Vasilev, E. R. Grela, D. Kowalczyk-Pecka and M. B?kowski

Energy supplements used in feed rations for cows can affect the yield, composition and quality of milk. To improve the energy balance in the periparturient period and the composition of milk fat in the subsequent weeks of lactation, it can be profitable to supplement the feed with a mixture of a glucogenic preparation and free fatty acids.

AN17114Effect of duration of altrenogest treatment on farrowing rate and litter size of gilts

F. De Rensis, C. Mazzoni, R. Saleri, A. Scollo, K. J. Plush and R. N. Kirkwood

Gilt retention and fertility are the bedrock of swine farm profitability, and methods to improve these measures that do not impact animal welfare are needed. This study examined the optimal use of an in-feed product for oestrus synchronisation and improved breeding management. The observed higher fertility associated with a longer feeding period provides for evidence-based recommendations for optimal product use.

Milking cows once daily (OAD) is one solution to labour problems in the New Zealand dairy industry. Comparison between 302 commercial herds milking OAD and 2424 paired herds milking twice-a-day (TAD) indicated improved reproductive performance, a change in reasons for cows exiting the herd, and the use of fewer Holstein–Friesians in OAD herds. However, a decrease in milk production of ~11% was experienced in the first season, which was not recouped relative to TAD herds. Farmers considering OAD should evaluate the trade-off between the ability to decrease costs to offset decreased production and impacts on labour and/or lifestyle.

On many pasture-based dairy farms in Mediterranean climatic zones, lactating cows also rely on conserved forage for periods as the main dietary forage source. We showed that switching gradually over 10 days from a grazed pasture to a grass silage-based diet increased milk yield significantly compared with an immediate changeover without any adaptation period. In regions where grazed pasture becomes unavailable, a gradual introduction of grass silage to cows will be more profitable for producers.

The present study evaluated the effects of supplemental nano-selenium (NSe) and nano-zinc oxide (NZn-O) particles during in vitro maturation (IVM) on DNA damage of cumulus cells, glutathione concentration in bovine oocytes, subsequent embryo development and the re-expansion rate of vitrified warmed blastocysts. Optimal embryo development was partially dependent on the presence of NSe and NZn-O during IVM. NSe and NZn-O during oocyte maturation act as good cryoprotective agents of vitrified, warmed blastocysts.

Great efforts have been made to identify nutritional ways to mitigate emissions of the greenhouse gas methane from ruminants. Several medicinal plants containing specific plant secondary metabolites were screened as sole substrates and as supplements, individually as well as in binary combinations. Combining A. paniculata and P. longum mitigated methane without side effects on ruminal fermentation. In vivo experiments yet to be conducted will show whether this combination has the potential to be developed as feed additive for ruminant nutrition.

AN17516Farmed red deer home range, habitat use and daily movement patterns in a Southland, New Zealand, tussock grassland over calving and lactation

A. J. Wall, G. W. Asher, M. S. Netzer, M. G. H. Johnson, K. T. O'Neill, R. P. Littlejohn and N. Cox

In the South Island high country of New Zealand large tracts of native-tussock grasslands are increasingly being used for red deer farming. The present study used GPS-tracking and GIS technologies to identify the main habitats that red deer use in these tussock-grasslands, the typically daily behavioural patterns of the deer, and the likely long-term consequences of their behaviour on this type of grassland ecosystem. The results of the present study will aid in the future management of this type of grassland under deer farming.

Enzymatic treatment significantly reduced the crude fibre and increased the crude protein contents of palm kernel expeller (PKE). However, these improvements were not reflected in the growth performance of broilers chickens, and the benefits of enzymatic treatment diminish when higher percentages of PKE were included in the broiler diets.

AN16184Comparison and relationship between meat colour and antioxidant capacity of different pig breeds

Wei Chen, Qi-fan Zeng, Hai-peng Xu, Guo-feng Fang, Shou-dong Wang, Chuan-hao Li, Yan-dong Wang, Hui Wang and Yong-qing Zeng

Comparative study between Chinese native pig breeds and commercial crossbred pigs can provide information on meat colour and antioxidant capacity of different breeds. This is a preliminary study on antioxidant capacity in Chinese native pig breeds, exhibiting higher antioxidant capacity than commercial crossbred pig. This discovery could provide a new perspective on meat colour and antioxidant capacity, and these results implied that there was a strong relationship between meat colour and antioxidant capacity.

Methionine is one of the materials for protein synthesis. This study investigates the effects of dietary methionine deficiency followed by replenishment on growth performance and carcass characteristics of lambs. The results show that dietary methionine deficiency in early life retarded the growth and development of lambs. However, the growth rate was not retarded during the 28 days of subsequent methionine replenishment stage.

Taste and smell are the consequence of millions of years of vertebrate evolution for sensing environmental chemical cues critical for balancing dietary selections. However, the no-choice feeding regimes in most farm animals leaves the nutritionist with the challenge of dietary choices. This review highlights the role of sensing of essential and non-essential nutrients and bitter compounds on voluntary feed intake. Future research will gravitate around understanding the dialogue between the gut chemosensory system and the brain.

AN17166Regular estimates of herbage mass can improve profitability of pasture-based dairy systems

P. C. Beukes, S. McCarthy, C. M. Wims, P. Gregorini and A. J. Romera

Knowledge of herbage mass per paddock is important for managing rotational grazing on pasture-based dairy farms. The aim of the present study was to model a value proposition for collecting and using this information, with a value estimated at NZ$385/ha versus a cost of collecting of NZ$20-40/ha. This result can help farmers evaluate the effort of collecting the data versus the opportunity to improve the profitability of their businesses.

AN16832Antimicrobial drug usage and poultry production: case study in Ghana

Sherry Johnson, Kwasi Bugyei, Priscillia Nortey and William Tasiame

Poultry production is a huge source of animal protein to the people of Ghana. Drugs were commonly administered to the birds in a bid to achieve higher efficiency in production. This study determined the types of drugs used in poultry farming and found that drugs were used without heeding to withdrawal periods stipulated by the manufacturer. This practice could result in antimicrobial resistance and residue in poultry products.

Probiotics can have a beneficial effect on growth performance and immune indicators in chickens. The use of a probiotic preparation containing Enterococcus faecium and vitamin D3 and C during the entire fattening period in the amount of 0.25 g/L of water has a beneficial effect on the histology and microbiological composition of the small intestine of chickens. Administration of this probiotic preparation also stimulates immunity in the chickens and improves growth performance. Our research confirms the appropriateness of using probiotics in poultry nutrition.

AN16292The effect of lipid metabolism-related genes on intramuscular fat content and fatty acid composition in multiple muscles

Chendong Liu, Linyuan Shen, Jingjing Du, Xiaoqian Wu, Jia Luo, Qiang Pu, Zhendong Tan, Xiao Cheng, Jianguo Du, Qiong Yang, Shunhua Zhang and Li Zhu

Intramuscular fat and fatty acid composition significantly affect meat quality, but the regulation mechanism of lipid metabolism among multiple muscles is unclear. Here, we found seven genes associated with lipid deposition in muscle tissues, and identified the relationship between muscle fibre types and monounsaturated fatty acids/saturated fatty acids. These results added beneficial information to improve meat quality, and provided potential genetic markers for the study of fatty acid composition.

Beef heifer management to first mating affects growth in low-nutrition environments in the dry tropics. A study using 1368 heifers in six cohorts described highly variable annual growth, with compensatory gains in body condition, liveweight and hip height following low dry-season growth. This variability resulted in up to 67% and 25% of heifers weighing 100–150 kg and >150 kg at weaning, respectively, not reaching target weights by the end of first mating, with no significant benefit from low-level post-weaning dry-season supplementation.

AN16310Influence of exercise and dietary omega-3 oil supplementation on interleukin 1-Ra serum concentrations in Standardbred horses

Giuseppe Piccione, Claudia Giannetto, Daniele Bruschetta, Fulvio Congiu, Francesca Arfuso and Elisabetta Giudice

Dietary polyunsaturated fatty acids supplementation induces a reduction in the amount of pro-inflammatory mediators. We studied their influences on serum interleukin-1 receptor antagonist concentrations in horses subjected to regular training as a source of inflammatory reactions. A regular training program induces an inflammatory response 20 days after its starts; omega 3 fish oil supplementation had an influence on the inflammatory reaction starting form 30 days of supplementation.

Dietary supplementation with Allium hookeri and whey powder in pigs influences the quality of dry-cured meat. Due to the dietary supplementation with Allium hookeri and whey powder, the dry-cured meat has a longer shelf-life and higher sensory characteristics. In conclusion, the high quality of dry-cured meat can be developed by the dietary supplementation of Allium hookeri and whey powder.

Composition and colour of porcine meat are strongly involved in meat quality and may be affected by the nutritional management and the genotype of the animals. In this paper, we show that, even under identical nutritional treatments, significant differences exist on composition, mineral content, fatty acid profile and colour of meat between Iberian and lean pigs, at different growing stages. Characteristics such as the high amount of intramuscular fat, the great concentration of heme pigments and the high level of monounsaturated fatty acids are among the more relevant quality aspects of Iberian muscles.

AN16592Consequences of genetic selection for environmental impact traits on economically important traits in dairy cows

Purna Kandel, Sylvie Vanderick, Marie-Laure Vanrobays, Hélène Soyeurt and Nicolas Gengler

Selecting for environmental impact traits might have consequences we do not know currently. This study tried to get a first glimpse of what might be expected as correlated responses from currently selected traits. Because of the complexity of relationships among all the traits we want to improve, results showed that profound changes in current indexes might be required, not only simply adding environmental traits.

AN16728Commercial equine production in New Zealand. 1. Reproduction and breeding

Erica K. Gee, Chris W. Rogers and Charlotte F. Bolwell

Breeding mares are kept at pasture in New Zealand and reproductive efficiency is improving. However, Thoroughbred breeders face significant pressures from industry with a short breeding season that does not match the timing of the natural breeding season, and popular stallions are required to breed many mares. Breeding horses require excellent stud management and veterinary management to achieve industry targets.

AN16791Replacement of soybean meal by sunflower cake in heifers finished on pasture: meat quality

Rafael Henrique de Tonissi Buschinelli de Goes, Kennyson Alves de Souza, Ana Guerrero, Sara Letícia Nochi Cerilo, Alexandre Rodrigo Mendes Fernandes, Diego dos Santos Penha and Ivanor Nunes do Prado

The use of agribusiness co-products as replacers of other cereal grains can decrease costs on cattle feed. The aim of this work was to study the feasibility of replaced soybean meal by sunflower cake (up to 60%) in heifers finished on pasture. The qualitative and sensory characteristics of meat were not altered, proving the viability of this kind of feed replacement.

The intensive genetic selection over the past years has resulted in cows with high milk yields, but this increase has been linked to poor oestrus expression and mastitis causing financial losses. In Brazil there are no studies involving correlations between somatic cell score and production using random regression models. Favourable additive genetic correlations between somatic cell score, persistency and milk yield suggested that there has been a low indirect gain in somatic cell score and persistency.

AN16573A non-synonymous single nucleotide polymorphism in the paraoxonase 3 gene regulates meat quality in Berkshire pigs

Jeong-Wan Hur, Jung Hye Hwang, Seul Gi Kwon, Da Hye Park, Tae Wan Kim, Deok Gyeong Kang, Go Eun Yu, Sang Mi An, Il-Suk Kim, Hwa Chun Park, Jeongim Ha and Chul Wook Kim

The paper is about the selection method for high-quality pork. In the research, the investigators identified genetic markers that regulate meat quality in Berkshire pigs. These meat quality-associated markers can be applied to pig breeding to produce high-quality pork.

Capacity to manipulate feed intake in pigs provides a way to optimise productivity and profitability in production systems. Fundamental mechanisms regulating feed intake include constraints imposed by the gut, systems monitoring current and long-term energy status to increase or decrease intake, and hedonic, reward-related drivers, over-riding the normal regulated intake. Knowledge of these mechanisms can be used to identify practical strategies for either increasing or decreasing voluntary feed intake in pigs.

AN16784Feeding wet distillers grains plus solubles contributes to sarcoplasmic reticulum membrane instability

M. D. Chao, K. I. Domenech-Perez, L. S. Senaratne-Lenagala and C. R. Calkins

Past studies have shown that beef from cattle fed a high concentration of distillers grains was more tender than beef from cattle fed corn only. To understand why, this research characterised the muscle and lipid properties of meat from the different diets. Results suggested feeding distillers grains may increase tenderness, possibly by altering sarcoplasmic reticulum membrane integrity, resulting in more rapid intracellular calcium leakage to enhance the meat aging process.

Natural food preservatives derived from blood can be an alternative for artificial additives widely used in food and the pharmaceutical industry. Hydrolysates obtained by enzymatic hydrolysis of porcine blood were assessed for their antioxidant and antimicrobial efficacy. The study revealed that porcine blood hydrolysate (whole and fractions) can be a potential source of natural preservatives for shelf-life extension in food.

The results that weaned piglets were protected from bacterial endotoxins by placing piglets on a taurine-supplemented diet will provide theoretical basis for the application of taurine in piglets. Dietary taurine prevented weaned piglets from intestinal damage by lipopolysaccharide of Gram-negative bacteria. The beneficial effects of taurine were due to decreased stimulation of the immune response to lipopolysaccharide and an improvement in intestinal epithelial barrier function.

The harmful effects of inbreeding on reproductive traits are well known to breeders. The results obtained in the present study showed that inbreeding had undesirable effects on some reproductive traits in Markhoz goats; however, these effects were not significant. It can be concluded that mating system policy in the studied Markhoz goat population have been appropriate.

The paper is an introduction to a Festschrift held at Sydney University to acknowledge the contribution that John Langtree Black has made to animal science in Australia and the world. The extraordinary wide range of topics, disciplines and animal species covered by his research are outlined. Important contributions to advancing knowledge and to applying knowledge to rural industries and the community are highlighted.

AN16358Performance of finishing beef cattle fed diets containing maize silages inoculated with lactic-acid bacteria and Bacillus subtilis

Carlos H. S. Rabelo, André L. S. Valente, Rondineli P. Barbero, Fernanda C. Basso and R. A. Reis

Maize silage is widely used worldwide to feed dairy cows and beef cattle. In tropical conditions in particular, maize silage has low stability and its nutritive value declines when it is exposed to air after the silos are opened. The present study revealed that combining Lactobacillus plantarum with L. buchneri or Bacillus subtilis in maize silage is not effective in improving feed intake and growth performance of finishing feedlot beef cattle.

AN16821Effect of quality control, density and allele frequency of markers on the accuracy of genomic prediction for complex traits in Nellore cattle

Tiago Bresolin, Guilherme Jordão de Magalhães Rosa, Bruno Dourado Valente, Rafael Espigolan, Daniel Gustavo Mansan Gordo, Camila Urbano Braz, Gerardo Alves Fernandes, Ana Fabrícia Braga Magalhães, Diogo Anastacio Garcia, Gabriela Bonfá Frezarim, Guilherme Fonseca Carneiro Leão, Roberto Carvalheiro, Fernando Baldi, Henrique Nunes de Oliveira and Lucia Galvão de Albuquerque

The success of genomic selection depends on the accuracy of genomic predictions, which can be influenced by many factors such as genotype quality control, marker density and minor allele frequency. In the present study we assessed the effect of these three factors on genomic prediction of Nellore cattle and found no effect of quality control and marker density, whereas markers with low allele frequency showed poor prediction ability. Our results help identifying which genomic information should be used for genomic predictions.

In response to stress, short tonic immobility broilers showed better growth and adaptability performance than long tonic immobility broilers. The relationship between tonic immobility and the central nervous system that controls appetite and energy sensor is not clear. The results showed that in the hypothalamus tonic immobility had no significant effect on the gene expression of feeding and energy regulation factors; however, fasting activates adenosine monophosphate-activated protein kinase and glucocorticoid receptor signals.

Improved liveweight gain in the grasscutter requires adequate dietary protein supply, which is a function of the animal’s physiological state and feed. This experiment determined the protein requirement of growing grasscutters fed diets containing forage meal, and found 18% crude protein as the optimum. This discovery provides an opportunity for feed developers to utilise forage meal as an ingredient in grower-grasscutter diets.

AN16011Detection of heat produced during roughage digestion in ruminants by using infrared thermography

Márcia Saladini Vieira Salles, Suelen Correa Silva, Luiz Carlos Roma, Lenira El Faro, Carla Maris Machado Bittar, Celso Eduardo Lins Oliveira and Fernando André Salles

Infrared thermography contributes to animal nutrition studies as a non-invasive tool to capture heat digestion in ruminants. Infrared thermography was able to detect differences in the body temperature of animals associated with different fibre proportions in the diets. The sensitivity of infrared thermography in capturing small temperature variations and its non-invasive nature make it a useful tool in different fields of study that require the measurement of temperature differences of objects, plants, animals or humans.

AN16753Commercial equine production in New Zealand. 3. The racing and sport industries

Charlotte F. Bolwell, Chris W. Rogers, Erica K. Gee and Sarah M. Rosanowski

This review presents data on the size, scope and organisation of equestrian sport and racing within New Zealand. The keys features of which are shaped by pasture-based management and a large export focus for the Thoroughbred industry. Describing the racing and sport-horse industries is essential to aid understanding of the production process of the equine athlete in New Zealand.

AN17048Genotype by environment interaction for yearling weight in Nellore cattle applying reaction norms models

S. Ribeiro, J. P. Eler, V. B. Pedrosa, G. J. M. Rosa, J. B. S. Ferraz and J. C. C. Balieiro

Selection of production animals may be compromised when there is no knowledge of the relationships between genotype and the environment in which a particular animal is inserted. This work aimed to investigate the impact of the genotype environment interaction on the performance of cows in the postweaning phase. It was verified that in Nellore individuals there was no significant impact of the environment on the genotype of the animals, concluding that the same selection criteria can be adopted between the mentioned regions in the studied regions.

AN16242Effect of the inclusion of natural additives on animal performance and meat quality of crossbred bulls (Angus × Nellore) finished in feedlot

Carlos Alberto Fugita, Rodolpho Martin do Prado, Maribel Velandia Valero, Elton G. Bonafé, Camila Barbosa Carvalho, Ana Guerrero, Carlos Sañudo and Ivanor Nunes do Prado

Natural additives can modulate ruminal fermentation on high energetic density diets. The aim of this work was to study the effect of essential oils and yeast inclusion on cattle diets. Addition of natural compounds (oregano, castor bean, cashew oils and yeast) improved bull performance, without changing significantly meat characteristics. Natural additives could be an alternative for ionophores substitution.

Among various approaches, diet plays an important role in lowering livestock-related methane emission. Thus, the effect of various energy levels on enteric methane emission was evaluated at two different seasons in growing Murrah buffaloes. Methane energy loss as % GE intake was 13% lower during the winter season. The present study revealed that adjustment in feeding system energy level lowered enteric CH4 emission and will be helpful for intensive rearing under a tropical environment.

Live transportation of livestock is an important aspect of animal production. We transported diffident crosses of tropical/temperate breeds of heifers for 6 h along different road conditions in the tropics. We discovered that the crosses of the cattle did well during transportation on tarred road, but responded poorly when transported along rough untarred road. Thus, transportation along rough roads may compromise the animal welfare and health status.

AN17051Variability of the IGF2 locus in the Suino Nero Lucano pig population and its effects on meat quality

Amalia Simonetti, Andrea Rando, Paola Di Gregorio, Carmelisa Valluzzi, Annamaria Perna and Emilio Gambacorta

The Insulin-like Growth Factor 2 gene (IGF2) is known as an important regulator of growth, development and differentiation of skeletal muscle. In this study, the polymorphism of the IGF2 gene and the effect of IGF2 genotypes on the quality of meat from Italian autochthonous Suino Nero Lucano breed were investigated. IGF2 genotypes were associated with different effects on both muscle mass and meat quality characteristics. As a consequence, in the SNL population it is possible to choose sires and dams according to the destination of the final product.

AN17102Effects of immunocastration on the performance and meat quality traits of feedlot-finished Bos indicus (Nellore) cattle

J. F. M. Gómez, A. Saran Netto, D. S. Antonelo, J. Silva, G. A. Sene, H. B. Silva, N. P. Dias, P. R. Leme and S. L. Silva

Castration is a practice widely used in male cattle to reduce aggressive behaviour and improve meat quality. However, surgical castration negatively affects animal welfare, health and performance; therefore, immunological castration can be an alternative. Immunocastration decreases feedlot performance and improves meat quality compared with non-castrated males. Surgical castration and immunocastration affect performance and meat quality similarly, indicating that immunocastration can be used as a technique to replace surgical castration.

AN16698Utilisation of a mix of powdered oils as fat supplement in nursery- and growing-pig diets

R. Sá, M. Gandarillas, A. P. Schinckel, D. Kuppenheim, J. Salgado, C. M. Cox, R. E. Larraín and E. Vargas-Bello-Pérez

Pigs are fed mainly with cereals as energy sources, and fats and oils, due to their high energy content, represent an attractive ingredient. Nonetheless, fats are usually more expensive than cereals and high levels in the diet are not well tolerated by pigs. In this study, we tested the use of a crystallised powdered oil mix produced by a technology process and included at levels close to 10% and this resulted in improved digestion efficiency and in a better growth performance in pigs.

The mitochondrial function in skeletal muscle determines the growth performance and meat quality of broilers. This study aims to elucidate the effect of tonic immobility duration and chronic corticosterone administration on the mitochondrial function in pectoralis major muscle of broilers. We found that tonic immobility duration but not chronic corticosterone administration affected the mitochondrial function. Our results suggest that short tonic immobility broilers might be a good target for broiler breeding.

Tedera has agronomic characteristics ideally suited to Mediterranean-like climates that allows it to provide high quality green forage during summer and autumn. Three sheep grazing experiments were carried out in Western Australia with the objective to evaluate sheep production during summer and autumn with tedera as the sole diet. These experiments clearly demonstrate that tedera can be used to reduce or eliminate expensive hand feeding during summer and autumn using the simplest and least expensive grazing management; continuous grazing.

There is still much controversy concerning whether forage should be included in the calf diet during the pre-weaning period. The aim of this study was to determine the responses of calves to forage type and forage provision age. The results indicate that forage provision had no negative effect on calves, which justifies the supply of forage to young calves, even at an early age.

AN16717Performance, hepatic function and efficiency of nutrient utilisation of grazing dairy cows supplemented with alkaline-treated Jatropha curcas L. meal

Jocely G. Souza, Lucas M. G. Olini, Claudio V. Araujo, Simone Mendonça, Joanis T. Zervoudakis, Luciano S. Cabral, Ibukun M. Ogunade and André S. Oliveira

Jatropha meal (JM) is an emergent source of protein for ruminant feed, but the presence mainly of phorbol esters limits its use. We evaluated the effect of JM treated with sodium hydroxide (to reduce phorbol esters) in concentrate supplements to grazing dairy cows. Sodium hydroxide treatment reduces phorbol esters in JM; however, its inclusion in concentrate supplements reduces diet digestibility and performance of dairy cows.

In South America, animal agricultural systems have a great responsibility in greenhouse gases emissions. In the present study, we demonstrated that one strategy to reduce the enteric methane emission contribution is the use of high-quality pastures. The single use of high-quality pastures could lead to a reduction of ~14% of the methane emitted per unit of intake, compared to lower quality pastures with higher fibre and lower protein contents.

Mixture silages with high silage quality and safety were reported. Different type and application rates of by-products, inoculants and their combinations were used to improve the mixture silages. The inoculants, application rates and type of by-products improved silage quality and reduced the saponin and the combination of three factors performed best.

The objective of this study was to investigate the effect of three methods of oral selenium-enriched yeast supplementation (maternal, post-calving, and maternal and post-calving) on the blood characteristics and growth of Holstein dairy calves. Maternal supplementation improved the growth and health characteristics of calves at calving time. However, post-calving and pre- plus post-calving supplementation were not more effective than pre-calving supplementation alone.

AN16423Effect of the acute heat stress on serum endotoxin concentration and the expression of TLR4 mRNA in liver of Arbor Acres broiler chickens

Shu-cheng Huang, Ya-Fen Fu, Mujeeb Ur Rehman, Kun Li, Yan-fang Lan, Wei Liu, Hou-qiang Luo, Hui Zhang, Li-hong Zhang, Ya-nan Hao and Zong-xi Tong

Heat stress is a very challenging environmental condition for broiler chickens that has caused considerable economic losses worldwide to the poultry industry. To investigate the relationship between gut-derived endotoxin and liver injury via detecting Toll-like receptor 4 (TLR4) expression, the heat stress experiment of broiler chickens found that the upregulated TLR4 expression was triggered via gut-derived endotoxin in heat stress-induced liver injury. This may provide new insights for the therapeutic manipulation of heat stress in poultry.

AN17008Dingo baiting did not reduce fetal/calf loss in beef cattle in northern South Australia

Greg Campbell, Andrew Coffey, Heather Miller, John L. Read, Anthony Brook, Peter J. S. Fleming, Peter Bird, Steve Eldridge and Benjamin L. Allen

Dingoes are known to prey on calves, although separating predation from other causes of calf loss has long been difficult. The present study found that where the use of poisoned meat baits, or other influences, caused dingo activity to be half that on unbaited control sites, there was no significant difference in calf survival. Because we did observe predation on calves, it is likely that either the baiting method did not reduce dingo numbers sufficiently to protect calves, or that uncontrolled cow age or cattle diseases confounded results.

Exogenous phytases have won global acceptance by the chicken-meat industry; nevertheless, the extra-phosphoric effects of phytase are still being realised. As outlined in the present review, the extra-phosphoric effects of phytase, especially in relation to intestinal uptakes of sodium, glucose and amino acids, hold importance in relation to the digestive dynamics of starch and protein and, in turn, poultry performance.

AN16147Quality characteristics of meat from triceps brachii muscle from steers and heifers finished on high-concentrate diets containing increasing concentrations of linseed oil

E. A. Oliveira, A. A. M. Sampaio, B. L. Rosa, W. Henrique, T. M. Pivaro, V. G. Carvalho, L. G. A. Cirne and S. K. Duckett

High concentrate diets with increasing linseed oil concentration were offered to steers and heifers to evaluate quality traits of meat. The higher linseed oil concentration increased the levels of important fatty acids such as n-6 and n-3. The inclusion of linseed oil is a strategy to produce meat with benefits for human health.

AN16818Effect of freezing on the quality of meat from broilers raised in different rearing systems

A. Giampietro-Ganeco, J. L. M. Mello, R. A. Souza, F. B. Ferrari, B. M. Machado, P. A. Souza and H. Borba

This study evaluated the effect of freezing (−18°C) for 12 months on the qualitative characteristics of breast, thigh and drumstick meat from antibiotic-free, conventional, organic and free-range broilers. Freezing chicken meat did not prevent colour and pH changes or occurrence of lipid oxidation and did not promote a reduction of aw to levels unfavourable to microbiological development.

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