In any environment, appropriate plant–animal interactions are essential to achieve sustainable livestock intensification, food and nutritional security and improved livelihoods of farming communities. This study reviews grazing and browsing research to understand contrasting ruminant-agricultural practices to provide a solid foundation for developing sustainable farming practices. The outcome differentiates livestock feeding strategies and their impact on land-feed-use efficiency.

κ-CN plays a critical role in the formation and stabilisation of casein micelles, and influences the manufacturing properties of milk. Although genotypes for κ-CN polymorphisms were associated with protein and solids-not-fat content of milk in Hostein and Brown Swiss, they had an effect on fat content of milk in Jersey. B allele was associated with increasing milk quality, therefore, selection of B allele could provide economic advantage for increasing milk quality.

In recent years, dairy cattle breeders have shown an increasing interest in selection for functional traits such as calving difficulty. The aim of the present study was to estimate genetic correlation between calving difficulty and productive and reproductive performance of Holstein cows. Exploitable genetic variation in calving difficulty, productive and reproductive traits could be applied in designing future genetic selection plans for Iranian Holsteins.

Lamb mortality is an important production and welfare issue worldwide. In this paper we demonstrate how litter size affects the maternal genetic contribution to lamb survival and compare alternative approaches to defining the ewe rearing ability trait, ignoring or accommodating variation in lamb survival due to litter size. The accuracy of genetic evaluation for rearing ability may be improved if the impact of litter size on lamb mortality is considered.

Phosphorus deficiency in cattle grazing rangelands may have severe adverse effects. Single photon absorptiometry was used in on-farm experiments to measure tail-bone mineral density and thus diagnose bone phosphorus. Prolonged phosphorus deficiency markedly reduced mineral density of tail-bone in young-growing and reproducing cattle, but not in mature cows. Single photon absorptiometry may be valuable to diagnose long-term phosphorus deficiency in cattle.

Increases in the efficiency of microbial protein synthesis (EMPS) of cattle grazing tropical pastures should lead to increased liveweight gain through increased total metabolisable protein supply. Rumen degradable protein (RDP) supply from tropical pastures is low; hence, increasing the dietary supply of RDP is a strategy to increase EMPS. Our study showed that only high amounts of RDP supply to the rumen, in the form of true protein, resulting in increased EMPS. However, at lower intakes of RDP, which were formulated to achieve EMPS in the range suggested in the feedings standards, there was no difference in supplying the RDP as non-protein nitrogen or degradable true protein.

One of the main nutritional challenges imposed on animals is feed restriction; however, it is still unknown how goats of different sexes react physiologically to the continuous restriction of nutrients. This study investigated the effect of sex on metabolic changes in growing goats subjected to levels of feed restriction. Our results show that under feed restriction, females and males react differently physiologically and are able to use different metabolic responses to meet their energy and protein demands.

Determining the fatty acid status of chickens requires invasive methods to obtain blood samples for analysis. We postulated that measuring the fatty acid composition of preen oil, which is externally secreted from the uropygial gland of live chickens could be an alternative non-invasive method. However, the results showed that the fatty composition of preen oil is not a suitable indicator of the whole blood fatty acid profile in chickens.

What is effect of yeast preparations on fatty acids and flavour which are closely related to beef quality? A research was conducted, of which results indicated that yeast products had little effect on individual fatty acid but improved the tenderness of beef. The findings will be beneficial in regulating beef quality by yeast preparations in the near future.

A high-concentrate diet commonly causes digestive disorders in finishing lambs. This study aimed to evaluate effects of sugar beet pulp and canola seeds on ruminal fermentation and morphology of finishing lambs. Partial use of sugar beet pulp and roasted canola seed inclusion successfully optimized ruminal environment and had beneficial effects on morphology of the rumen in lambs fed a high-concentrate diet.

To meet global demand, increases in meat production are essential. Although conventional feed costs may limit the feedlot finishing of beef cattle, this can be circumvented by the use of agro-industrial by-products. The use of crude glycerin in cattle diets can increase animal performance and reduce the cost of feeding.

Increasing ruminal input of buffers from the diet or saliva yields bases or buffers such as ammonia could prevent a depression in ruminal pH. Supplementation of banana flower powder either with or without urea could enhance rumen ecology and fermentation efficiency. Therefore, banana flower powder is potentially used as a rumen buffer agent for high-producing dairy cattle promising to replace sodium bicarbonate.

Phosphorus has nutritional, environmental and economic importance due to its high cost and potential for soil and water contamination. We evaluated the effect of phosphorus supplementation, with or without other minerals, ionophore and antibiotic, on animal performance, feeding costs and phosphorus utilisation in Nellore bulls finished in a feedlot. Minerals, ionophore and antibiotic were not necessary to ensure health and performance of feedlot Nellore bulls, with emphasis for the reduction of pollution and feeding costs in Brazilians feedlots.

To improve productive performance, the findings of this study should be useful for the feed and broiler chicken industry. The present study was conducted to investigate the effect of reducing dietary protein with methionine supplementation and subsequent feeding of a low-energy diet on growth performance of broiler chickens. The results indicate that growth performance and carcass quality were significantly improved by this method, which may be an appropriated tool for improving production of broiler chickens.

Residual feed intake has been recommended as a selection criterion for beef cattle to increase individual feed efficiency. Efficient or low residual feed-intake cattle have a significant economic advantage since they consume less feed than expected for their weight and rate of gain compared with their more inefficient or high residual feed-intake counterparts. The results do not support the hypothesis that an increase in feed efficiency, evaluated in growing animals in feedlot-performance tests, decreases enteric CH₄ production.

The inclusion of forage legumes in ruminant production systems presents nutritional, economic and environmental benefits. The aim of the present study was to evaluate the effect of different levels of inclusion of peanut hay on the nutritional value of diets based on dwarf elephantgrass hay. It was found that including peanut hay at up to 330 g/kg of dry matter in dwarf elephantgrass-based diets is sufficient to maximise the digestible-OM intake.

Reduction of enetric methane production from ruminant animals through the use of natural plant products is important because it causes global warming and energy loss to animals. Medicinal plant extracts, when tested on feed in the laboratory, reduced both enetric methane produced and energy loss by increasing feed digestibility. These plants can be used as replacements for artificial growth promoters in the meat and dairy industries to prevent antibiotic resistance syndrome in humans consuming animal products and animals can achieve faster maturity weight with lower methane emissions.

Bos indicus cattle are often castrated after six months of age without pain relief. Measures of pain that include pedometry, blood cortisol concentrations, and baulk and crush scores were used to characterise post-surgical castration pain and determine whether perioperative lignocaine or meloxicam or both reduced pain. Pedometer measures and cortisol concentrations proved useful and showed that strategic use of analgesics is viable in extensive farming situations and provides benefit to animals undergoing castration.

Animal performance and behavioural responses were evaluated under different production systems, throughout two seasons. Time of the day and especially the seasons influenced behavioural responses and animal performance. Meat production can be increased when the system includes rotation with crops (soybean and maize). Silvopastoral systems provide Nellore steers with a more comfortable and preferred environment for idleness and rumination.

In extensive production systems, native pasture availability decreases in winter, thus, ewes are undernourished during gestation. We subjected pregnant ewes to two different levels of pasture allowances, both followed by an increase in nutrient supply during the last third of gestation. Ewe-lamb behaviours at birth, lambs’ growth and feeding behaviours during rearing were unaffected by the level of pasture allowance.

The present study examined the effect of changes to the national inventory on the emission intensity of milk production of 41 Australian dairy farms previously assessed using the Dairy Greenhouse Gas Abatement Strategies calculator. The national mean emission intensity of milk production has increased, although individual farm emissions have either increased or decreased, depending on a range of factors. Methane from waste management has emerged a new ‘hot spot’, which will need consideration in terms of mitigation options moving forward.

The assignment of maternal parentage, although time-consuming and expensive using traditional methods, is essential for genetic improvement. The temporal frequency that cows and calves walk to water was measured to determine whether maternal pairs could be remotely identified and resulted in greater than 90% of calves being correctly assigned. This has the potential to greatly increase maternal parentage recording within extensive beef herds, therefore identifying superior genetics and resulting in more profitable beef enterprises.

Twenty young Cika and 20 Simmental bulls were finished post-weaning on two diets and slaughtered at similar carcass weights. Cika bulls produced carcasses with a higher dressing percentage, more fat and less tendons and bones. The Longissimus thoracis muscle of Cika bulls had a lower pH, higher redness, yellowness and drip loss, and a more intense flavour.

When animals are exposed to a high level of stress, the animal’s body undergoes physiological changes as a means of maintaining homeostasis, thus negatively affecting the quality of meat produced. This study investigated breed and sex differences in response to pre-slaughter stress and the effects on stress indicators in the blood, muscle and overall meat quality attributes. The ewes and Dorper breed perceived the slaughter process to be more stressful compared with rams and the Merino breed.

Because of bad repercussions from using antibiotics and other chemical preparations, there was a dire need for natural alternatives. Our work aimed to investigate the impacts of using peanut skin powder on growth and health of broilers. Peanut skin powder lowered the amounts of carcass fats and minimised blood cholesterol, creatinine and urea, which means healthy chicken meat was gained.