Nutrients exert control of physiological functions in animals through their ability to alter gene transcription by interacting with transcription regulators within cells (‘nutrigenomics’ effect). Molecular techniques have allowed the discovery of gene networks controlling nutrigenomics responses in livestock. Since nutrition, health, and performance interact continuously and respond to changes in environment and physiology of the animal, application of holistic approaches is central for uncovering key molecular players involved in the animal'sadaptations to changes in nutrient supply and environmental conditions.

In the Brigalow Belt bioregion of Australia, clearing native vegetation for agriculture since the 1960s has altered hydrology and nutrient cycling over 36.7 million hectares. Long-term monitoring at the Brigalow Catchment Study has quantified changes in hydrology and soil fertility as a result of land-use change. Agricultural systems established soon after clearing were initially highly productive; however, productivity has since declined in accordance with declines in soil fertility.

Empirical studies in extensive rangelands are needed to quantify relationships between short-term foraging behaviours (e.g. minutes to days) and longer-term measures of animal performance. We found that two daily measurements of foraging behaviour, mean grazing-bout duration and mean velocity while grazing (both calculated at a 5 min resolution), can explain 62% of the variation in weight gains of free-ranging yearling steers grazing semiarid rangeland.

To remain viable, livestock businesses need to build resilience to climatic and market variability by regularly producing a profit. The farm-management economics framework was used to conduct a contemporary assessment of livestock enterprises in the semiarid rangelands of Queensland. Existing small ruminant enterprises were profitable and resilient alternatives, based on contemporary prices. However, when changing from the predominant beef cattle enterprise, and incurring significant capital costs to do so, financial risk was substantially increased, which has implications for property managers.

Virtual fencing technology has the potential to be used for intensive grazing systems, while reducing the labour involved with these systems. This study compared utilisation and grazing pressure at the fence line between virtually fenced and electrically fenced sheep, using an intensive grazing method. Pasture consumption was similar between the two groups, indicating that the use of virtual fencing does not affect grazing behaviour in sheep. Further work should be conducted in larger flocks and by using automated systems.

There are many different equations to estimate metabolisable energy content of ruminant feeds by different international feeding systems. This study compared 24 equations to predict metabolisable energy content of forage sorghum. There were differences between equations based on whether metabolisable energy content was predicted from digestibility or chemical composition. As such, applying these different equations will markedly affect ration formulations.

High prices for goats in Australia due to high international demand has resulted in a transition from opportunistic harvesting to more managed production systems for Rangeland goats. There is limited information available to establish feeding strategies to maximise growth rates of goats within these managed production systems. The present paper demonstrates that the highest rates of liveweight gain of young male Rangeland goats is when they are offered a high energy supplement.

Steers on a low-protein diet showed bacterial modification correlated to feed efficiency, whereas bacterial growth in the most efficient steers relied on the animal’s capacity to recycle nitrogen as a response of low dietary ammonia content. These outcomes may facilitate the selection of highly feed efficient cattle fed a low-protein diet.

Intertidal estuarine environments expose oysters to extreme environmental temperatures. This can increase microbial pathogens in oysters, making them more susceptible to diseases. The study looked at the microbes in Pacific oysters and how they changed in a viral infection, at different seawater temperatures. Increased seawater temperature was associated with pathogenic microbes and a higher susceptibility to disease, indicating its role as a key risk factor in oyster health.