Animal Production Science
Volume 58 Number 2 2018
AN15738Genetic and phenotypic parameters for reproduction, production and bodyweight traits in Australian fine-wool Merino sheep
Reproductive performance is one of the main profit drivers of the Merino sheep industries. With an increased emphasis on lifetime production and reproduction in Merino sheep, it is important to consider the genetic relationship between production and reproduction traits for yearling and adult expressions. The analysis and definition of life time reproduction traits require careful consideration and more work in this area is needed.
As part of the national beef cattle genetic evaluation in Australia 50 935 Angus and 50 930 Limousin calves were scored for docility. Genetic parameters for docility score were estimated using a threshold animal model from a Bayesian analysis. The heritability of docility score was estimated as 0.21 and 0.39 in Angus and Limousin, respectively. Weak but favourable genetic correlations between docility score and production traits indicate that selection to improve temperament can occur without having an adverse effect on growth, fat, muscle and reproduction.
AN16165Detection of candidate genes for growth and carcass traits using genome-wide association strategy in Chinese Simmental beef cattle
Detecting major genes, which control important economic traits in livestock, is meaningful to cattle breeding. We tried to explain the phenotype variance in genomic level, and explored the candidate genes for cattle growth and carcass traits using genome-wide association studies analysis. This study detected a total of 18 candidate genes and their harboured associated regions, which will facilitate mark-assist selection in Chinese Simmental cattle.
AN16107Genetic parameters for fatty acids in intramuscular fat from feedlot-finished Nelore carcasses
Reports of genetic parameter estimates for fatty acid (FA) profile are scarce for zebu breeds, and it is important to known whether selection is feasible to decrease harmful FA and increase health beneficial FA. The aim of the present study was to estimate genetic parameters of beef FA composition of intramuscular fat in Nelore bulls. The results of this study should help seek strategies for genetic selection and/or genetic-based diet management to enhance the beef FA profile in zebu cattle.
AN16138Priming anoestrous Corriedale ewes with progesterone and gonadotrophin-releasing hormone causes cervical tissue remodelling due to metalloproteinase-2 (MMP-2) activity
This paper provides evidence of collagen remodelling in the cervix of anoestrous ewes induced to ovulate with progesterone and GnRH. The activity of MMP-2 collagenase (but not of MMP-9) was higher on Day 1 after the induced ovulation than on Day 5, inversely to the collagen concentration, demonstrating that activation of MMP-2 is a key factor of cervical collagen remodelling in anoestrous ewes around induced ovulation.
The cryopreservation process compromises the sperm DNA integrity, and spermatozoa with a high level of damaged DNA might have low potential for fertilization. In this study the comet tail measures were used to assess the extent of DNA damage to frozen-thawed spermatozoa and detected marked inter-boar variability to cryo-induced sperm DNA damage. It can be suggested that the comet-assay parameters have the potential to be a powerful tool to improve the sperm evaluation of post-thaw semen quality.
AN16002Nitrate supplementation has marginal effects on enteric methane production from Bos indicus steers fed Flinders grass (Iseilema spp.) hay, but elevates blood methaemoglobin concentrations
This experiment quantified the methane abatement potential of calcium nitrate for extensively managed beef cattle. Nitrates provide an alternative sink for H that would otherwise support methanogenesis. Elevated concentrations of methaemoglobin indicate that replacing urea with nitrate in supplements for use in the northern rangelands is inappropriate where supplement intake cannot be controlled and forage quality is seasonally variable.
AN16175Effects of phytase, calcium source, calcium concentration and particle size on broiler performance, nutrient digestibility and skeletal integrity
High dietary calcium concentrations in poultry diets have a negative effect on bird performance, due mainly to a reduction in phytate-phosphorus digestibility. To counteract this, diets are supplemented with inorganic phosphorus and phytase. The ability to replace high dietary calcium concentrations with lower dietary calcium concentrations supplied by a highly soluble calcium source has the potential to alleviate the problems associated with high dietary calcium while maintaining optimal bird performance and skeletal health.
AN16322Utilisation of giant taro (Alocasia macrorrhiza) root meal with or without coconut oil slurry by layers and broilers
The effects of feeding giant taro root meal with or without coconut oil slurry on the performance of layers and broilers were investigated. Replacement of dietary maize at a level greater than 10% of the meal depressed performance of both egg- and meat-type birds. Supplementation with coconut oil slurry allowed utilisation of 20% of the meal by laying hens, but had no effect in young broiler chickens.
AN16226The impacts of dietary Nigella sativa meal and Avizyme on growth, nutrient digestibility and blood metabolites of meat-type quail
The continuous increase in prices of traditional feedstuffs like corn and soybean meal made a dire need for low-cost, untraditional and balanced diets. Nigella sativa meal was included in quail diets as untraditional feedstuff to reduce costs and to examine its impacts on productive and health aspects. Great results were obtained by the inclusion of 15% Nigella sativa meal in growing quails diets, which positively supported growth and feed utilisation.
AN16265Effects of substituting corn with steam-flaked sorghum on growth, digestion and blood metabolites in young cattle fed feedlot diets
The research about sorghum and its processing as feed is necessary to to expand the application scope of sorghum. Partial substituting ground corn grain with steam-flaked sorghum grain in beef cattle diets could improve growth performance. The optimum substitution rate of ground corn grain with steam-flaked sorghum grain was 2/3 (DM basis).
AN16025Frequent handling of grazing beef cattle maintained under the rotational stocking method improves temperament over time
We assessed beef cattle temperament in the Brazilian Amazon region where the deforestation for cattle production is a cause of concern, and the intensification of beef cattle production using rotational grazing systems arises as an alternative. We found that the rotational stocking method improves cattle temperament over time, resulting in less reactive animals when compared with those kept in an alternate stocking method.
AN15719Effect of weaning age and milk feeding level on pre- and post-weaning growth performance of Sahiwal calves
Pre-weaning feeding cost may be reduced by early weaning of calves, offering solid feeds at an early age, or using milk replacers. In this study, early or late-weaning coupled with low- and high-milk combinations were tested to see growth performance of Sahiwal calves. It was concluded that offering milk at 15% of bodyweight and weaning at 8 weeks was a low-cost feeding strategy.
AN16028Effects of a single injection of Flunixin meglumine or Carprofen postpartum on haematological parameters, productive performance and fertility of dairy cattle
The administration of a NSAID at parturition should reduce the associated inflammation and pain associated with calving but the evidence of a clinical benefit of their use and the relative dosage in cows with puerperal disease is limited and equivocal. The aim of the study was to evaluate the effects of a single injection of Flunixin meglumine (FM; intramuscular) or Carprofen (CA; subcutaneous) within 12 h after calving on dairy cattle haematological parameters, dry matter intake, productive performance and fertility. The findings evidenced that a single injection of FM or CA to non-febrile cows immediately after parturition positively affects the metabolic adaptation of the cows at the onset of lactation and this aspect can positively influence reproductive performances and the culling rate.
AN16180Productivity and profitability of forage options for beef production in the subtropics of northern Australia
Targeted use of high quality forages is an intensification strategy that has the potential to improve the profitability of northern beef businesses through increasing enterprise turnover and productivity. Our study provided comparative data for forage, animal and economic performance for a range of forage options for dryland beef production in northern Australia. The data indicated that perennial legume-grass pastures, and particularly leucaena-grass, resulted in greater profitability than annual forage crops or perennial grass and that this was primarily due to the relatively low forage costs for perennial legume-grass pastures (compared with annual forage crops) combined with their high productivity.
Nuisance flies are important arthropod pests in cattle feedlots, with the potential to cause production loss and health impacts on livestock, workers and surrounding communities. Population models were developed for fly abundance and showed that fly numbers could be predicted using time-of-year and rainfall. The models provide a useful tool for optimising the timing of fly-control treatments, such as insecticide or biopesticide applications, adding to the effectiveness of integrated pest-management programs for the control of nuisance flies in feedlots.
AN15804Differences between sexes, muscles and aging times on the quality of meat from Wagyu × Angus cattle finished in feedlot
We assessed the characteristics and aging time of meat from Wagyu × Angus animals of both sexes. Females had the best marbling score, greater fat content, and less shear force. Crossbreeding with Wagyu and Angus is interesting to produce high-quality beef. Meat aging reduced shear force and increased ultimate pH of the longissimus thoracis. We conclude that aging for 7 days is already sufficient to produce an acceptably tender meat based on shear force values.
AN16111Fatty acid profile of ghee derived from two genotypes (cattle–yak vs yak) grazing different alpine Himalayan pasture sites
Fatty acid profile of ghee obtained from cattle × yak hybrids during a transhumant movement cycle between 2600 and 4500 m a.s.l. was influenced by pasture site. The hypothesis that yak ghee contains, in general, higher proportions of functional FAs than does ghee from cattle × yak hybrids (cattle × yak) could not be verified. However, yak ghee contained higher proportions of long-chain n-3 polyunsaturated fatty acids. More studies are needed to exclude possible factors of influence.
The factors affecting the fatty acid profile of meat and those that are related with its quality, should be determined in a mixture of the major muscles, since humans consume different parts of the carcass. The fatty acid composition of muscles reflects that of the milk source (maternal or artificial) but the response of each muscle was not the same for all the fatty acids. Lower slaughtered age may provide a more beneficial fatty acid profile, from a human health point of view.
The quality of three muscles from farmed fallow deer (Dama dama) was analysed in the study so as to compare the functionality of these muscles after storage in vacuum packaging. The results indicated a different technological quality of the analysed muscles, and thus a need to further explore the background of these differences as well as the factors affecting the maturation of deer meat during chilled storage.
Pre-slaughter process is considered a high risk of animal stress, which can cause carcasses bruising that represent significant losses for the meat industry. Our results indicated that specific conditions of sex, loading facilities, cattle handling, transport time, hauling-truck types, truck animal-load density and unloading time influenced the occurrence of bruises. Thus, special handling practices and personnel training measures should be undertaken to mitigate losses pre-slaughter.
Improving smallholder cattle feeding practices in Cambodia is necessary to reduce labour demands and improve income from cattle raising. The present study investigated the socioeconomic impacts of forage technology adoption with results showing significant time savings for forage growing households and reduced involvement of women and children. Forage technology should therefore be recommended to cattle-owning households as an alternative to traditional feeding practices to save time, increase income and improve livelihoods.