Starch is the chief dietary energy source for chicken-meat production; however, the factors that impact most on its utilisation have not been investigated thoroughly. This paper reviews the literature relevant to starch digestion and glucose absorption from the perspective of chicken-meat production. The foremost factor influencing starch utilisation may be the interaction between starch and protein digestive dynamics.

In a previous study we significantly increased the long-chain omega-3 content of chicken meat by feeding a diet containing short-chain omega-3 from flaxseed oil. The present study, using almost 4000 broiler birds housed under near-commercial conditions, demonstrated the same flaxseed oil diet improved growth rate and feed conversion efficiency from hatch to 6 weeks of age without negative effects on health or mortality. This supports the commercial viability of short-chain omega-3 diets for the chicken industry.

The proportion of female lambs was previously shown to be higher when ewes were fed a diet high in omega-6 fatty acids both before and, following the time of mating. In the present study, the proportion of female lambs was higher when Border Leicester × Merino ewes were fed a diet high in omega-6 compared with omega-3 fatty acids either pre-mating only or both pre- and post-mating. The largest increase in the proportion of female lambs was observed when ewes were single-bearing compared with multiple-bearing. The mechanism resulting in the diet high in omega-6 influencing the sex ratio of lambs appears to operate before or around conception but is yet to be determined.

Nutrition during pregnancy is important for a successful gestation but it may also be important for the postnatal growth and development of the lamb. The results of this study demonstrated that maternal nutrition level during mid-gestation influences growth performance, muscle fibre types and number, muscle fibre cellular characteristics and carcass characteristics, but not birthweight and meat quality of the lamb after weaning at the end of finishing period.

To seek an explanation for the poor performance (e.g. high mortality, carcass quality) of runt piglets, the effect of birthweight and age on body composition and energy stores was assessed. Strangely, birthweight had no effect during the suckling period. This indirectly confirms the importance of feed (composition and energy) intake during the fattening phase as an explanation of the poorer performance at slaughter of runt piglets.

Livestock feeding systems rely heavily on cereals; locally available agro-industrial by-products can replace such conventional feedstuffs, often imported, reducing the cost of production even in terms of carbon footprint. Carob pulp contains substances that may negatively affect production levels and welfare; this study demonstrated that it can partially substitute barley in lamb diets, at relatively high level of inclusion, without harming the animals. Use of carob pulp could be a sustainable alternative feed resource easily to manage at farmer level.

Calf birthweight information is used as an indicator trait for calving ease in animal selection to minimise the risk of dystocia. The objective of this study was to estimate genetic parameters for birthweight of Iranian buffaloes using a Bayesian approach. The results of the present study indicate that exploitable genetic variation observed for birthweight could be considered in designing future selection programs for Iranian buffaloes.

Artificial weaning is one of the greater stressors for farm animals. Two-step weaning with nose flaps decreases behavioural signs of discomfort after definitive separation. We compared the behavioural changes in calves after using nose flaps for 7 or 21 days before definitive separation. Results indicate that the response is similar after using nose flaps for those lengths.

Molasses supplements can provide a valuable source of energy for growing cattle in northern Australia, but the efficiency of use of energy in molasses may vary with characteristics of accompanying forage. Our experiments showed that good growth rates in steers fed molasses and forage could be achieved, especially with forage of low nutritive value, but that digestibility of the forages decreased as molasses content of the diet increased. We conclude that the feeding standards for cattle require modification before they can be accurately used to predict growth for cattle fed tropical diets.

Agricultural industries face the challenge of maintaining and expanding production to meet global food requirements with fewer resources, while producing less greenhouse gas. This study quantified energy and water use, land occupation and greenhouse gas from a diverse range of beef production systems in eastern Australia, finding that impacts are sensitive to productivity factors and climatic conditions. Beef utilised land unsuitable for alternative foods that require crop land, and improving productivity was identified as a way to lower greenhouse gas emissions.

Production losses from livestock affected by toxins associated with some varieties of perennial ryegrass are occasionally extreme in Australia relative to New Zealand. Concentrations of toxins were studied and the ratio of ergovaline : lolitrem B was generally greater for Victorian pasture compared with New Zealand. The effects of the vaso-constrictive ergot alkaloids (including ergovaline) combined with that of the relatively high solar radiation on ruminants’ heat load were considered most important with respect to severe perennial ryegrass toxicosis in Australia.

This study suggested predicting the mechanical properties and ultrastructure of eggshells when egg weight was equal. A local breed had a higher resistance to eggshell breakage than commercial laying due to its longer palisade layer. Length of the palisade layer plays an important role in eggshell strength, therefore palisade layer should be considered in selection programs for improving eggshell strength.

Productivity increase of Japanese quail as a source of animal protein for human feed is desired. Construction of a multi-trait selection program to improve egg performance depending on aggregate breeding value estimation could give a great effect in correlated selection response, which has been evidenced through the present study. The present results could be helpful in programs aimed at improving animal production for intended institutions on national levels.

Milk production is a function of the number and secretory activity of mammary epithelial cells. Heat stress induces cell apoptosis, disturbs the biological activity and arouses intracellular thermotolerance responses of bovine mammary epithelial cells. Under heat stress, with increasing cell apoptosis number and upregulation of pro-apoptotic genes, the expression of anti-apoptotic genes was stimulated to a high level to prevent cell damage and maintain cell survival.

Accurate prediction of breeding value for calving difficulties is required to reduce its incidence in beef herds in Australia. This study provides breed-specific genetic parameters for calving difficulties, birthweight and gestation length for several beef breeds in Australia. These estimates will be used in the genetic evaluation of calving difficulties for BREEDPLAN to predict breeding values for calving ease in beef cattle.

Lambing ease (LE) is an important trait that affects animal welfare and profitability in sheep enterprises. This study examined the genetic parameters for LE and its genetic correlations with birthweight and gestation length by comparing different datasets and models. Higher phenotypic variance and direct heritability were found in single-born lambs than estimates in twin-born lambs. Direct genetic and maternal genetic effects were significant for LE. Estimates of direct heritability for LE using linear approaches were similar to those using threshold approaches (after transferring to observed scale). Lambs with greater birthweight and longer gestation length had more lambing difficulty. These genetic parameters are now used in the Sheep Genetics evaluation system.