Many studies have reported the importance of providing adequate nutrients to pregnant cows for increased reproductive efficiency, with reduced intervals between births and higher calf growth rates. However, studies evaluating the capacity of tropical grass pastures to supply sufficient nutrients for high productivity of cows during pregnancy and lactation are scarce. The present study demonstrated that in grazing Nellore cows, prepartum supplementation may increase cows’ performance and calf weight at birth, and postpartum supplementation may improve performance and reproductive efficiency.

Colostrum production and colostral immunoglobulin concentration can compromise twin lamb survival, reducing productivity and profitability on-farm. Two studies were undertaken to evaluate if protein supplementation to ewes consuming a high-starch diet during late gestation could improve colostrum production and increase colostral immunoglobulin concentration. Protein supplementation did not increase colostrum production nor colostral immunoglobulin concentration in ewes who were in adequate body condition pre-lambing.

Colostrum production following birth is integral for lamb survival, providing energy and preventing infection by supplying immunoglobulins. This study evaluated whether supplementing niacin (vitamin B₃) to late gestation twin-bearing ewes could increase colostrum production, immunoglobulin concentration and postnatal lamb growth. Niacin provision at 5 g/day for 2 weeks before lambing did not increase colostrum production, immunoglobulin G concentration or early lamb growth.

High intake of methionine (Met) or deficiency of a vitamin acting on its metabolic pathway (e.g. vitamin B₆) can cause high blood homocysteine concentrations. Supplementation with vitamin B₆ at 3.58 vs 1.58 mg/kg improved feed conversion of finishing pigs but did not improve the metabolisation of increased blood homocysteine caused by higher levels of standardised ileal digestible Met +cystine (SID Met + Cys). Thus, the main contribution of this study is the data it provides about the required levels of dietary SID Met + Cys associated with vitamin B₆ supplementation for finishing pigs.

Methane accounts for 2–12% loss of dietary gross energy in ruminants and is a potent greenhouse gas. Tropical fruit peels can be simply collected and exploited; therefore, they were assessed as an alternative feed ingredient in ruminant diets. Tropical fruit peel reduced methane gas production in vitro and improved DM degradability in situ.

Reduction in cost of poultry feed is possible by optimising the dietary protein level and also improving its digestibility with protease supplementation. Protease was supplemented (0 and 4000 u/kg) in diets containing three graded levels of protein in egg laying chicken diet. Protease supplementation improved egg production, feed efficiency, albumen quality and protein utilisation. Protease supplementation could improve the egg laying performance and protein (nitrogen) retention with a concomitant reduction in nitrogen excretion from the poultry farming.

Effects were investigated of using gelatin as a partial protein source with protease in broilers diets. Gelatin at higher inclusion levels decreased performance; however, protease supplementation reduced these losses to some extent. Considerations when introducing gelatin is the unusual amino acid profile, which may be further reduced by choice of more effective enzymes.

In Argentina, livestock is the main source of greenhouse gas emissions, and nitrous oxide (N₂O) emitted from excreta is an important contributor. This study of N₂O emission was conducted in the main livestock region of the country, with cold winters; although the difference in gas emissions was only 5% between soils with and without livestock during winter, the difference could be important if extrapolated to the entire livestock area. Future studies, already under way, will allow to see their weight within the total annual emissions.

Measuring residual intake and gain (RIG) allows identification of animals that present higher growth rates and proportionally lower feed intake than expected, without leading to an increase in adult bodyweight. The identification of efficient animals by RIG can assist in the early slaughter without having negative impacts on meat quality. The RIG has a great potential for improvements in the sheep production system, such as reductions in feed and labour investments due to a shortening in the production cycle.

In meat exporting countries, cattle producers have a challenge to achieve high-quality carcass traits for different export markets. Superior sire lines for carcass traits and feeding practices intending to obtain greater weight gains during the winter phases were applied to improve carcass traits. At the same carcass weight, steers presented better carcass yield and higher weights of striploin and sirloin cuts when severe restrictions were avoided during the first winter phase and sires with high expected progeny differences for the ribeye area were used.

The adaptive potential of the Santa Inês breed to extensive grazing is recognised, so these sheep are widely used in this system. The Santa Inês is important mainly due to its environmental resistance and ability to produce under adverse climate conditions, as well as the potential as a maternal lineage for commercial production. The in vivo evaluation by computed tomography of the of body traits on meat production animals can be used both to identify and select animals with the best productive characteristics and to make choices regarding marketing the products of these animals, allowing advances in sheep meat production.