Animal Production Science
Volume 57 Number 9 2017
RESEARCH FRONT: Orange EverGraze proof site
ANv57n9_FOForeword to ‘Orange EverGraze proof site’
Grazing by sheep and cattle has reduced productivity and increased soil erosion and loss of perennial grasses in the native grasslands of southern Australia. Large-scale grazing experiments produce reliable information on interactions between plant and livestock needed to identify the best management for farmers to use to improve their grasslands. This special edition of Animal Production Science provides recommendations to help farmers improve production and environmental benefits of native pastures.
AN15856Designing a grazing-system experiment for variable native pastures and flexible lamb-production systems
Grazing systems represent complex interactions between animals, pastures, soils, climate and management. This paper describes the process used to characterise the potential productivity of variable native pastures, and the development of flexible systems. Incorporating spatial variability into the design, and flexibility into the management of grazing experiments, should lead to results that are better aligned with commercial grazing practices.
AN16154In a native pasture, landscape properties influence soil moisture more than grazing management
There are competing views on whether grazing management, from continuous to high intensity rotational grazing, can significantly change farm profitability and sustainability. It is unknown if changes to grazing management changes pasture mass and composition and in turn stored soil water. This study shows that the underlying landscape and climate dominates the changes to soil moisture and no grazing management effects could be detected in the measured soil moisture.
AN15861Increased production and cover in a variable native pasture following intensive grazing management
The appropriate intensity of grazing management to improve pasture production and to sustain native species composition is still debated. This study found increasing the intensity of grazing management resulted in higher herbage mass, growth and ground cover of pastures, while landscape position largely influenced pasture composition. Increasing the intensity of grazing management may help limit the degradation of pastures.
Greater knowledge of the diet selection of animals managed within grazing systems is essential to enhance animal performance. The diet selection and performance of sheep grazing a native pasture was assessed and a major driver of selection – the green : dead ratio (or greenness) of herbage – was identified. Monitoring the greenness of a pasture may provide a management trigger to enhance the production of animals within a rotational grazing system, in particular during periods of higher requirements.
The intensity of grazing management required for optimal animal production in native grasslands of south-eastern Australia has been debated. This paper describes how the intensity of grazing management influenced lamb production per head and per hectare. While continuous grazing had higher production per head than 4- and 20-paddock rotational grazing, more ewes were run in the 20-paddock system to maintain similar production per hectare to continuous grazing.
AN16129Post-experimental modelling of grazing systems to improve profit and environmental outcomes using AusFarm
Assessments of grazing systems are often constrained by management decisions and seasonal conditions, which can lead to conflicting results when comparing systems. This paper used post-experimental modelling to gain a better understanding of the influence climate and management decisions can have over a long-term period. In understanding the impact of these management decisions and climate influences, strategies can be developed to improve management of the system.
AN16678Assessing the profitability of native pasture grazing systems: a stochastic whole-farm modelling approach
Changing grazing practices in the high rainfall zone of southern Australia have seen a shift towards more intensive rotational grazing systems. This paper assessed the long-term financial implications of investing in additional fencing and water infrastructure required for higher intensity grazing rotations in native pasture systems. Profitability was primarily driven by stocking rate, however the infrastructure cost associated with high levels of paddock subdivision also reduced profitability.
AN16599Synthesis of system outcomes for a grazing-management experiment in temperate native pastures
The present paper synthesises the outcomes of a grazing-system study investigating the intensity of grazing management. Increasing the intensity of grazing management resulted in higher lamb production per hectare, but had lower whole-farm profitability due to higher infrastructure costs. The farming-system approach successfully integrated field research with modelling to help develop a full understanding of the impact of this management system.
The prediction of feed intake is important in poultry production. To include environmental effects on feed intake is necessary to calculate the daily total heat production. The present study showed that the re-parameterisation of heat-loss equations are efficient to predict the heat flux in broilers under different environmental conditions.
AN16257Effect of in ovo injected prebiotics and synbiotics on the caecal fermentation and intestinal morphology of broiler chickens
The administration of bioactive substances directly into chicken embryo may result in stimulating the favourable bacterial profile in the gut of growing chickens. The main results of the present study show that the injection of beneficial bacteria into the incubating egg together with the substance which stimulates its growth, improved development and physiological functions of the chicken’s digestive tract.
AN15709Cottonseed meal is a suitable replacement for soybean meal in supplements fed to Nellore heifers grazing Brachiaria decumbens
An important source of protein used in the diets of animals of production is soybean meal, which can present high prices. Cottonseed meal could be a suitable replacement to soybean meal in supplements to grazing beef cattle. This study evaluated the effect of substituting soybean meal with cottonseed meal in supplements fed to grazing heifers. No relevant differences were found in animal performance, indicating that cottonseed meal can be a suitable and possibly cheaper replacement to soybean meal.
AN16119Effects of Bacillus amyloliquefaciens LFB112 in the diet on growth of broilers and on the quality and fatty acid composition of broiler meat
Consumers are becoming increasingly interested in food containing a high concentration of polyunsaturated fatty acids (PUFA), which are considered as functional ingredients to prevent cardiovascular disease and other chronic diseases. In order to achieve desirable meat, we have investigated the effects of Bacillus amyloliquefaciens LFB112 in the diet on the growth of broilers and on the quality of broiler meat and found that dietary supplementation of B. amyloliquefaciens LFB112 enhanced average daily gain, average daily feed intake and improves meat colour and fatty acid composition of meat from broilers. Our study showed that PUFA composition of meat from broilers was profoundly affected by diet and can be approached, at least in part, from a microbial point of view, suggesting that intake of meat from broilers fed a B. amyloliquefaciens-supplemented diet might exert protective effects on cardiovascular disease.
AN16202Effects of wet feeding and enzyme supplementation on nutritional value of wheat screenings for broiler chickens
Wheat screening (WS) is a cheap source of energy and other nutrients for use in broiler diets; however, it has a considerable amount of non-starch polysaccharides (NSP). The negative effects of NSP may be decreased by the supplementation with exogenous enzymes and/or with wet feeding of wheat-based diets. In the present study, broiler performance was improved by the inclusion of WS to the diet and also by wet feeding, but not by enzyme supplementation.
AN15132A quantitative and qualitative approach to the assessment of behaviour of sows upon mixing into group pens with or without a partition
The presence of a concrete partition (a short wall, 2 m long × 1.6 m high) running through the middle of group pens had a positive influence on sow behaviour at mixing. Sows in pens with a partition lay down and stopped investigating or eating/searching for food sooner, and were scored as more ‘calm/relaxed’. Even subtle differences in housing design (in this case, retention of a concrete partition as part of refurbishment) can positively influence the demeanour and activity patterns of sows.
AN15799Effect of bedding materials during transport on welfare indicators and microbiological quality in lambs
This research tackles the welfare of lambs during transport to slaughterhouse and its implications on the hygienic quality of the carcass. It specifically focuses on the bedding material required for the transportation of the animals and can be taken as a base to drive future legislations integrating the whole production system. Regarding the results, no significant differences have been found among the materials tested (sawdust rice husk, and double layer of sawdust).
AN16048A regional model of sheep lice to study the effect on lice prevalence and costs for Australian farms using a range of treatment efficacy in combination with other lice control strategies
A model of the Australian flock prevalence of lice was used to examine the value of various methods of treating sheep for lice after shearing when combined with other lice management options. The model showed that high-cost treatment could be cost-effective provided it resulted in eradication, and should be combined with adequate biosecurity for purchased sheep. These two methods in combination could provide a dramatic reduction in lice prevalence and in costs associated with lice.
AN15768Feeding management, production and performance of 13 pasture-based dairy farms in a Mediterranean environment
Supplementary feeding practices on Western Australian dairy farms are an important factor affecting productivity and profitability. Farmers in the region generally provide concentrates to cows in the milking parlour, but some also offer mixed rations with forages and concentrates outside the parlour. Our data indicate performance was highly variable between farms and systems, and mixed ration feeding systems did not increase intake or milk production. Management appears to have a greater influence on farm performance than feeding system per se.
AN15574Impact of liveweight, fat and muscle sire breeding values on ewe reproduction is minimal but variable across Australian grazing systems
Australian sheep producers have the potential to improve reproductive rates through optimising ewe body condition across the production cycle. Reproductive records from the Information Nucleus Flock and Sheep Genetics datasets were analysed to examine the influence of sire breeding values for liveweight, fat and muscle across a variety of production environments. The sire breeding values for liveweight, fat and muscle had very little association with the reproductive performance of their daughters, on average, but the association varied across flocks from unfavourable to favourable.
AN15651On the profitability of irrigated fodder production: comparative evidence from smallholders in Koga irrigation scheme, Ethiopia
Economically feasible irrigated fodder production can help to manage the problem of livestock feed shortage in subsistent and commercial livestock systems and to diversify farm income. In this study we stochastically simulated profit obtainable from irrigated Rhodes grass seed production to assess the economic feasibility of the practice and to inform related investments and risk management decisions under smallholders’ conditions. The results show the absolute and comparative profitability of the commodity and the possibility to scale out irrigated fodder production both as a source of livestock fodder and farm income.