The underlying premise of this paper is that agriculture is a major determinant of human health through the supply of food derived from both plant and animal sources. In other words, nutrition is the conduit between agriculture and human health. Against this backdrop what potential role do mycotoxins, produced by fungal plant pathogens, play in determining global food and feed supplies?

The housing of laying hens in cages is thought to adversely impact hen welfare, in part because, in the absence of a nest box, pre-laying activity by the hen typically increases as the hen ‘searches’ for a nest before ‘sitting’ to lay her egg. Although pre-laying locomotion has been cited as a welfare indicator for hens, it would seem that pre-laying behaviour is in fact quite flexible, and instead, the time spent sitting before egg laying may be a more relevant welfare indicator. These findings may alter the focus of research investigating the importance of housing, including the provision of nest boxes, for hen welfare.

Feeding the world is increasingly challenged by rising global population, climate change and escalating energy costs. Anticipated future increases in animal protein in the human diet pivot on the future cost and availability of livestock feeds. Maximizing feed-use efficiency and development of new feed sources for all classes of livestock is required to meet future demand for livestock products.

Within a day, decisions such as ‘when’ to begin, ‘which’ frequency and ‘how’ to distribute meals determine ruminants’ diurnal grazing pattern, and thereby nutrient supply for metabolism and growth. This work investigates the physiological basis of these decisions and examines evidence for managing this pattern to improve animal performance. Grazing management altering the intensity and temporal distribution of meals can increase and differentiate nutrient supply to and productivity of grazing ruminants.

Native North Americans made textiles from the woolly coat of the American bison, which insulated both bison and man from severe winter conditions. American bison grazed in Victoria produced 1.2 kg of fibre, which after processing had a fibre diameter similar to fine Merino wool and a mid-length suitable for woollen processing. The production of significant amounts of fibre indicates that fibre could form an important source of income in bison enterprises.

Cashmere is made into the ultimate soft textiles, which modern consumers demand in a wide range of colours. The whiteness and brightness of cashmere varies considerably between farms and in response to other raw fibre properties. These variations in the whiteness and brightness will affect the ability to dye cashmere to bright and pale shades and have implications for farm and animal management.

The relationships between skin characteristics and fibre quality in Merino sheep are known but these same relationships have not been investigated in alpacas. We quantified the number, type and arrangement of skin follicles in alpacas and correlated this with fibre traits. The S/P ratio, secondary follicle density and liveweight were important determinants of alpaca mean fibre diameter.

Wool growth from Romney sheep is affected by seasonality, reproduction and pasture quantity and quality, such that a wool staple may have a weak point along its length, affecting staple tenacity. This characteristic is heritable, and some sheep are genetically able to grow stronger wool staples in which the fibres are thicker and longer. It is also correlated with the ability of ewes to wean more lambs and grow more wool. Genetic selection to overcome seasonal effects on wool quality is possible although it is currently not economic.

Wiltshire sheep avoid flystrike and have lower husbandry costs if they shed all their fleece and do not need shearing. New Zealand Wiltshire sheep were selected either for increased or decreased greasy fleece weight at yearling shearing in spring. Fleece weight was heritable, and the correlated response in wool shedding was measured in summer and sheep with lower fleece weight shed more wool at younger ages. Breeders who wish to eliminate the fleece and its associated animal health problems could incorporate Wiltshire shedding genes and rapidly select sheep that do not need shearing.

Genetic variation in sulphur, calcium, magnesium, manganese and other trace metal content of Merino fleeces is associated with brightness, yellowness and photostability. Higher levels of Ca, Mg and Mn are associated with less bright, less photostable and yellower wool while fleeces high in Fe would be less bright and whiter but tend to photoyellow faster then those lower in Fe.

Vasectomised rams have proven to be beneficial in improving the breeding performance of ewe lambs. The aims of this study were to examine the effects of condition score and timing of exposure to vasectomised rams on the reproductive performance of ewe lambs. Ewe lambs of greater condition score display higher rates of reproductive performance and there is a limit to how early ewe lambs can be successfully exposed to vasectomised rams.

Cows that rebreed on time each year are vital to an efficient beef breeding cow herd. This experiment examined postpartum anoestrous interval and pregnancy rate to rebreeding in beef-cross-dairy breed first lactation cows. Jersey component cows offered advantages in fertility traits and may be worthwhile incorporating into beef-breeding herds.

Identifying optimal nutrition for twin-bearing ewes is often a problem for farmers. This study indicates that twin bearing ewes can be restricted until at least day 136 of pregnancy with few implications for their offspring. Little difference was also observed between offspring born to ewes over the body condition score range of 2.0 to 3.0.

Little is known about the impacts of feeding a ewe post weaning on her subsequent lambs. This research aimed to establish whether there was a production advantage from feeding ewes to gain versus maintain liveweight during the six weeks post-weaning, and found no effect on production in the subsequent lambing season. This may indicate that feeding levels of ewes immediately post-weaning can vary without affecting subsequent production.

The stocking rate of ewes at lambing has the potential to influence the survival rates of their lambs, thereby changing profitability. This study showed that the survival of twin lambs was 24% lower (63% compared with 83%) when ewes were stocked at 30 rather than 16 ewes/ha in small paddocks sheltered with hessian rows. These results suggest caution in using high densities or flock size of ewes during lambing, at least in this shelter type.

The ewe-lamb bond is considered to be important in the survival of the newborn lamb. Ewe movement and ewe-lamb contact was investigated at two stocking rates in an artificial shelter environment, with ewes at the higher stocking rate travelling further and having more contact with their lambs, but crossing through shelter rows less often. Lamb survival was lower at the higher stocking rate suggesting the nature of the contact rather than duration is important.

For many mammals it is not clear whether growth is determined primarily by suckling demand from the infants or by the ability of the mother to produce milk. We addressed this question in red deer by providing a milk production stimulus to hinds and found that this had no effect on growth of their calves. This means that growth of red deer calves is dictated by the calves themselves and that there may be little benefit from selecting red deer hinds for their milk producing ability.

Yard weaning is a viable option to manage the weaning transition or Merino lambs. Three on-farm experiments in the NSW Central Tablelands showed improvements in growth rates and survival compared to normal paddock weaning practices although the results were inconsistent between experiments. Further work is needed to determine the optimum duration of confinement and composition and method of delivery of the ration.

The maternal environment is perhaps the most critical factor regulating birth weight and subsequent growth. This study confirms that fetal development is reduced by mid-gestation in a restricted maternal environment and the affects persist until weaning. Improved maternal nutrition does not alleviate this apparent constraint, at least in singletons. Constrained fetal growth could have implications for long-term performance and warrants further investigation.

This study set out to investigate the effects of early and mid to late ewe pregnancy nutrition on the anatomical development of twin-fetuses. No differences were found on fetal body weight or size measurements although minor effects were observed on some tissues and organs. The results suggest that farmers can limit ewe nutrition in early pregnancy with only minor consequences on the fetus.

Manipulating ewe liveweight during pregnancy is considered a mechanism to improve on-farm performance. Analysis of data from multiple experiments established that additional mature ewe liveweight during pregnancy has a limited influence lamb performance. Once ewes have attained nutritional requirements for pregnancy, further feeding to increase the ewe's liveweight is unlikely to alter lamb birth and weaning weight.

It is unknown if singleton, twin- and triplet-born ewes are metabolically different and little is known regarding the long-term impacts of maternal nutrition during preantral follicle development. This study aimed to determine if dam pre-breeding nutrition and birth rank affected the metabolic responses of 18-month-old ewes to a glucose and insulin tolerance test. There were few differences between single-, twin- and triplet-born ewes; however, dam pre-breeding nutrition appears to have lasting effects on β-HBA metabolism. These differences would need to result in measurable animal performance differences to be of commercial importance.

The longer term impacts of being born to an adolescent mother are unclear. This study investigated the growth, milk production and reproductive performance of ewe offspring born to adolescent or mature dams. Whilst ewe offspring born to adolescent dams were lighter at birth and up to 12 months of age, beyond this up to 3 years of age no differences were observed in liveweight or productive performance between ewe offspring born to either adolescent or mature dams.

Declining terms of trade is the reality for farmers. The ‘whole farm systems approach’ can be used to compare the cash, profit, wealth and risk impacts of alternative futures for a farm business. Options to increase profit may involve intensifying or extensifying, and/or reducing or increasing the size of the venture. This approach allows the exploration of relevant questions for a farm business.

Fast degrading perennial ryegrass (Lolium perenne L.) is a desirable characteristic to select for because it can result in increased feed intake by grazing ruminants. Seventy-seven perennial ryegrass accessions were examined to estimate soluble, potentially degradable and indigestible fractions using an in sacco technique and it was found that a large range in genotypic variation was present in all degradation parameters. The result presents plant breeders with ample opportunity to select for fast degrading perennial ryegrasses.

Methane yield from ruminants is positively correlated with mean retention time of digesta, which is known to be influenced by the hormone triiodothyronine (T₃). The results of this study indicate that increasing plasma concentration of T₃ reduces digesta retention time, especially retention time in the hindgut and leads to a reduction in enteric methane yield. Further work is warranted to assess whether plasma T₃ concentrations may be indicative of enteric methane yield.

Intake is the main limitation in tropical grasses to achieve high levels of animal production. The present experiment demonstrated that increasing the soluble carbohydrate content by plant breeding or supplement will increase intake of total dry matter but not that of fibre. It is concluded that the underlying fibre characteristics of the diet limit intake and cannot be overridden.

The yield of meat cut from a carcass represents the major proportion of the value of the animal and, thus, ways to predict this yield indirectly are important. Work to investigate alternative ways to predict this yield is the subject of this paper. Such predictions allow processors the opportunity to reward producers who turn-off high yielding lambs as they reduce processing costs.

We hypothesised that genetic variation within gene regions that are known to be important for meat tenderness and long-chain omega-3 fatty acid biosynthesis would be useful for explaining variation in these traits in the Australian sheep population. We discovered genetic mutations in muscle protease genes that were associated with large effects on meat tenderness, but genetic variation in genes involved in long-chain omega-3 fatty acid biosynthesis showed no association with omega-3 content in lamb.

Texel ram and ewe lambs were compared for performance and meat quality traits of LL and SM. Although meat from ram lambs was significantly tougher, had less fat and was lighter in colour, the differences were small.

Feed efficiency is an important trait in beef cattle. Genes that are expressed in the liver were used, with 84% accuracy, to classify steers into their respective high or low feed efficiency line. This indicates that the approach of measuring the expression of genes in body tissues has great potential in the search for gene markers for important traits in cattle.

Mob-based walk-over weighing is a new management tool available to sheep farmers for improving nutritional management of their flocks. This study proved that frequent, in-paddock measurement (walk-over weighing) provides flock average liveweights similar to traditional weighing approaches. This is an important finding for the sheep industry, as it provides valuable information for flock nutrition management and removes the need for mustering sheep into yards for weighing.

Leucaena pasture based systems are amongst the highest producing cattle fattening systems in the world. Molasses supplementation provided a strategy to better utilise the high CP content in leucaena/grass pasture systems, maintain high stocking rates and achieve higher live weight gains than pasture alone. This provides flexibility to producers in maintaining high stocking rates when herbage mass is low and also a means to increase live weight gain most likely by enhancing microbial protein production in the rumen.

Poor dry season nutrition coupled with diseases such as coccidiosis leads to reduced survival of young cattle in northern Australia. A pen feeding experiment carried out to determine the effect of dietary monensin inclusion showed a growth response of about 0.1 kg/day in steers fed supplements promoting either a low or medium plane of nutrition. Monensin has a key role in improving the nutrition and welfare of young grazing cattle.

Bali cattle are the predominant cattle breed reared by small-holder farmers across eastern Indonesia. Experiments were conducted to evaluate various feeding strategies which increased the liveweight gain of weaned Bali cattle to over 0.4 kg/day compared to 0.1 kg/day under existing management systems. Implementation of these findings may improve income and livelihoods of small-holder farmer households in eastern Indonesia.

Phosphorus deficiency in cattle is a major problem in many areas throughout the world. The addition of 25OH-vitamin D increased the apparent digestibility of both P and Ca, resulting in an improved retention of these minerals in steers fed a low-quality, high-fibre diet.

Improving the productivity of smallholder cattle enterprises in Indonesia requires greater and more efficient utilisation of feed resources. The aim of this experiment was to find the amount of tree legumes required to meet the maintenance requirements of an Ongole cow fed rice straw ad libitum, which was 12 g DM/kg W^0.75.day. This diet could be used for cattle with low energy requirements while higher quality feeds are directed to pregnant, lactating and growing cattle.

This study examines whether the differences on post-weaning liveweight gain in steers, as an intrinsic characteristic of the host, were associated with rumen fluid bacterial community. Molecular bacterial analysis suggests there was no link between hosts selected on the basis of liveweight gain with different rumen bacterial population profiles. This result expands the understanding of the concept that the host exerts an influence on rumen microbial populations.

Sheep that consumed a nitrate-containing diet gained almost the same liveweight as those fed a urea-supplemented diet, provided that animals were acclimated to nitrate gradually. Offering sheep a diet containing nitrate (also used as fertiliser) reduced methane emission from rumen fermentation.

Lice are an economically important parasite of sheep yet there is widespread speculation regarding the incidence of lice in central and southern New South Wales flocks. A survey that included visual and diagnostic inspection of sheep suggests lice infestations may have increased moderately since 2004. Producer education about the extent of the problem will facilitate improved regional control and preventative strategies.

The Australian wool industry needs to rebuild the national flock after years of decline due to drought and low wool prices. This overview discusses technologies that enable remote monitoring of sheep in the paddock. Incorporating such technologies during the rebuilding of the national flock could improve the efficiency of sheep production and provide a method to improve sheep welfare through increased monitoring without increased labour inputs.

Dag accumulation is a large problem facing unmulesed Merino Sheep and can be reduced by tail docking. This study investigated the relationship between different lengths of tails and dag score as well as the efficacy of the Te Pari Patesco knife. The Te Pari knife had less animals with more dags than animals in other treatment groups; however, this effect needs to be investigated further.

Caseous lymphadenitis (CLA) is prevalent in Australian Merino sheep flocks despite a vaccine being available for over 25 years. Abattoir surveillance data suggests the prevalence of CLA has declined to less than one-fifth of what was reported in 1995. In addition, a survey of producers within three NSW regions suggests CLA prevalence could be further improved through more effective communication of information on preventative management practices.