The Dynamic Conversion of Dietary Protein and Amino Acids into Chicken-Meat Protein

Abstract

This review considers the conversion of dietary protein and amino acids into chicken-meat protein and seeks to identify strategies whereby this transition may be enhanced. Viable alternatives to soybean meal would be advantageous but the increasing availability of non-bound amino acids is providing the opportunity to develop reduced-crude protein (CP) diets, to promote the sustainability of the chicken-meat industry and is the focus of this review. Digestion of protein and intestinal uptakes of amino acids is critical to broiler growth performance. However, the transition of amino acids across enterocytes of the gut mucosa is complicated by their entry into either anabolic or catabolic pathways, which reduces their post-enteral availability. Both amino acids and glucose are catabolised in enterocytes to meet the energy needs of the gut. Therefore, starch and protein digestive dynamics and the possible manipulation of this ‘catabolic ratio’ assume importance. Finally, net deposition of protein in skeletal muscle is governed by the synchronised availability of amino acids and glucose at sites of protein deposition. There is a real need for more fundamental and applied research targeting areas where our knowledge is lacking relative to other animal species to enhance the conversion of dietary protein and amino acids into chicken-meat protein.

The Impact of Digestive Dynamics on the Bioequivalence of Amino Acids in Broiler Chickens

“…Diligent research has been devoted to the complex task of identifying individual amino acid requirements for broiler chickens, which is ongoing. This quest has been reviewed [25], where ten sets of ideal amino acid ratios are documented. However, relative to pigs, amino acid requirements may be complicated by feathering in poultry.…”

Advances in the Nutrition of Functional Amino Acids in Healthy and Immunologically Challenged Birds

“…Thr is ranked as the third limiting AA [2,4] and is very important for the synthesis and maintenance of proteins in the body. About 30-50% of Thr, as well as some other amino acids, is directly used by the small intestine and is not available for extraintestinal tissues.…”

“…The establishment and reevaluation of nutrient requirements in poultry is a dynamic process due to constant increases in feed consumption, growth rate, and the amount of dietary protein, and amino acid (AA) transformed into body protein in chicken meat over time, as a result of genetic selection programs [1][2][3]. The advancement of each of these factors necessitates the constant labor of AA to maintain high levels of productivity, especially when we consider that in modern animal production, new concepts such as sustainability in meat production are emerging, as a result of the constantly increasing societal demand for food production through environmentally friendly practices.…”

Influence of dietary vitamin E and selenium supplementation on broilers subjected to heat stress, Part II: oxidative stress, immune response, gut integrity, and intestinal microbiota

“…Further, the need for agricultural products, especially protein sources, continues to rise with the growth rate of the world's population ( Bruinsma, 2009 ). Modern broilers are more efficient than other terrestrial food producing animals in converting plant-based nutrients into healthy protein ( Macelline et al., 2021 ), making poultry a key source for supplying the increasing demand of animal-based protein in the future. However, these animals are susceptible to elevated temperatures due to their anatomic features (e.g., lack of sweat glands), physiological state, and greater metabolic activity ( Sahin et al., 2009 ; Lara and Rostagno, 2013 ).…”