Selection for low worm egg count (wec) in sheep can rapidly improve resistance to worm infestation without adversely affecting other production traits. Moderate heritability for wec (0.2–0.3) was estimated from a large Merino industry dataset, along with generally small or close to zero genetic correlations with production traits. These genetic parameters have been incorporated into MERINOSELECT to provide Australian Sheep Breeding Values for wec and appropriate selection indices for wool and meat production.

The breeding value prediction and estimation of (co)variance components are essential for intended breeding plans by increasing economically important characters in livestock. The aim of this study was to estimate variance components, heritabilities and genetic correlations between 305-day milk yield, age at first calving and interval from first through second calving in Iranian buffaloes using Bayesian methodology. Heritability estimates for productive and reproductive traits implied that applicable genetic variations observed for these traits could be applied in designing future genetic selection plans for Iranian buffaloes.

Captive rearing of pheasants is currently a common practise in some European countries. Selection over three generations of common pheasants for a higher bodyweight at the age of 7 weeks in the present study resulted in higher weights of the carcass, legs, neck, heart and liver in selected pheasants. However, the selection resulted in lower proportions of some important carcass components. For further selection with regard to improvement in meat production it is additionally important to include feed consumption and morphometric characteristics.

Genomic selection has been suggested to increase the rate of genetic gain in livestock species. The current study, which focussed on three nonparametric machine-learning methods as well as Genomic Best Linear Unbiased Prediction (GBLUP), revealed superiority of GBLUP and Boosting in predicting genomic breeding values. Some variants of machine learning methods such as Random Boosting not only have high predictive accuracy, but also are efficient users of time and have a low memory requirement, all leading to them being recommended for future genomic evaluation.

In a previous experiment, the proportion of female lambs was higher when Merino ewes were fed a diet high in omega-6 fatty acids around mating. The present study examines the potential intergenerational effects of these diets. Although that effect was not significant here, the size of the skew in favour of female lambs when ewes were fed a High n-6 at mating was similar to previous studies and warrants further investigation with larger numbers of ewes. Enterprises preferring second-cross male prime lambs may benefit from feeding first-cross ewes a diet low in n-6 around mating.

The rearing of dairy cows with an improved ability to resist diseases improves animal health, welfare and farm profits. In this study the investigations of the relationships between improved animal immunity, stress management and efficient production formation revealed a favourable result. In future, the breeding of such animals provides a significant disease management strategy as well as reduced farm losses.

The use of exogenous enzymes in poultry nutrition is common in order to improve digestion, productivity and health of the birds. However, the efficacy of enzymes can be variable and it is necessary to explore the mechanisms involved in their effect under different nutritional conditions. The work presented herein found that feeding diets based on either soybean meal or canola meal resulted in changes to the effect of an exogenous protease and that protease addition may improve gut health of birds.

The capacity of intestinal microbiota to transform daidzein into equol has been well established in humans and other animal species, while the association of gut microflora and equol in swine is poorly understood. Urine and faecal samples from sows were found highly different in individuals, and intestinal microbiota were significantly correlated with equol production in the faecal and urine. Nutritionists could consider the effects of biological actions of soy isoflavones and their metabolites in livestock and possible application ways for promoting their health benefits.

Diet acidification was initially aimed at protecting feed against microbial contamination and spoilage. Currently, acidifiers are being researched as alternatives to the use of antimicrobial growth promoters (AGP) and show promising beneficial effects for broiler growth performance and gut function. Nutritionists could consider acidifiers as part of modern intervention strategies targeting broiler performance and health.

Lactating Holstein cows were fed 3-nitrooxypropanol, a biochemical compound designed to reduce methane emissions from cattle. Two doses of the compound were fed, 1250 and 2500 mg/day, reducing methane yield (g/kg dry matter intake) by 23% and 37%, respectively. There were no negative effects on animal performance, and nutrient digestibility was slightly increased indicating that the compound could be used to reduce the environmental impact of ruminant animal agriculture without compromising productivity of the animal.

Feed deprivation is a nutritional challenge for animals and little is known about the metabolism of minerals in goats under such conditions. We investigated the effect of feed restriction on macromineral metabolism of goats during pregnancy and observed that severe feed restriction decreased the maternal body mineral reserves and impaired fetus growth. Our results may help producers with feeding management strategies for pregnant goats, mainly during periods of feed scarcity.

Natural compounds with antimicrobial activity have been utilised to replace ionophores in ruminant nutrition, as the use of ionophores is becoming restricted because of their potential effect on microbial resistance to antibiotics. Chitosan, a natural biopolymer derived from chitin, is a potential modulator of ruminal fermentation. Chitosan increased propionate ruminal production, improved milk and protein yield, and, therefore, can be used as an alternative to ionophores in diets for dairy cows.

Little work has been done to clarify the effects of different iron (Fe) sources on Fe absorption in the intestine of broilers. This study was designed to evaluate the absorptions of Fe from different Fe sources, and the results indicate that organic Fe sources with stronger chelation strength showed higher Fe absorptions. This is of scientific and practical significance towards developing and applying new Fe additives with high Fe absorption in the production of broilers.

Mixtures of salt, urea and minerals offered free choice can provide cattle grazing rangelands with supplementary nutrients that are deficient in the pasture. However, it is often difficult to achieve intended target intakes by grazing cattle with these supplements because their intake is controlled by both innate palatability and learned responses. It was shown that inclusion of a palatable protein meal by-product in this type of supplement increased their voluntary intake by cattle.

Because of a decrease in availability and an increase in the price of corn, potato tuber meal (PTM) could be considered as an alternative feed to substitute for corn in the diet of broilers. The results of the present study to evaluate performance of broilers fed diets containing cooked PTM showed that PTM can replace dietary corn up to 40% during 22–49 days of age.

Rumen fermentation can be manipulated by many processes to improve fermentation efficiency and to mitigate methane production using plants containing bioactive products such as essential oils, saponins and tannins with antimicrobial properties, which may be exploited in ruminant production. Krabok (Irvingia malayana) seed oil and Flemingia (Flemingia macrophylla) leaf powder supplementation resulted in rumen fermentation enhancement and methane production reduction. Therefore, krabok seed oil and Flemingia leaf powder could be used as a rumen enhancer and further research under in vivo conditions should be conducted.

Bovine viral diarrhoea (BVD), one of the most important infectious diseases affecting cattle, is thought to show a subclinical course in most cases, yet few studies have assessed this rigorously under non-epidemic conditions. Here we used clinical characteristics to assess the prevalence of BVD in bovine production systems suspected of harbouring infection, and we found 33.7% of dairy farms, 30.6% of beef cow-calf farms and 40% of feedlots to contain at least one animal positive for BVD viral antigen. These results suggest that BVD could be associated to farms with clinical troubles, and that clinical diagnosis of active BVD infection can be helpful, particularly in dairy herds, where infection tends to be associated with higher rates of infertility, stillbirths and calf health problems.

Dairy goat farming has been shown to help improve the lives of Tanzanians. For biological reasons, research is often necessary in order to persevere in good production. This research focussed on understanding what motivates people to keep dairy goats, prominent attributes, and challenges to owning the best milking goats. The findings are important for sustainable goats’ milk production in Tanzania.

Summer-active forages are increasingly used in lamb production. However, there are concerns regarding the potential for off flavours in the meat due to the feed regime. Consumer and trained sensory panels assessed the flavour and eating quality of lamb finished on lucerne, plantain and conventional ryegrass. Few flavour differences were found between the feed treatments, demonstrating that lucerne and especially plantain can be used for finishing lamb in Australia, without negatively affecting flavour or eating quality.

Brazil is the world’s second beef producer and 80% of the Brazilian herd comprises Bos indicus cattle mainly Nellore breed. However, few studies investigate meat quality traits of this Zebu breed, especially bulls. Here, we provide results showing that lower backfat thickness and higher cooking losses are, to some extent, associated with meat toughness in Nellore bulls.

Nutritional and health properties of beef, which is an essential component of the human diet, may be influenced by a lot of factors. The aim of this study was to determine the impact of gender and feeding intensity on the fatty acids profile deposited in different locations on the beef carcass. The results showed the possibility of choosing the right way of using different fats from beef carcasses.

Being able to accurately predict body composition is paramount for efficient beef cattle nutrition management programs. Still, which equations might fit to broader scenarios remains to be answered. Thorough evaluation has shown that such approach is reliable, yet equations for different breeds should be developed in order to improve predictability. Biometric measurement equations are an excellent alternative for image-based systems to predict the optimum point of slaughter.

Meat consumption is considered essential in a healthy lifestyle, meaning the use of goat and sheep meat is increasingly popular, due to their nutritional and sensory features. This study uses legs of sheep and goat that had low commercial value (due to their age and weight) to develop two new meat products, which are safe and have promising sensory characteristics. It reports a strategy to enhance economic value to devalued meat and to provide consumers with good and differentiated products.