143 Nutritional advances in fetal and neonatal development: amino acid supplementation

Abstract

Abstract Nutrient requirements of grazing ruminants change throughout the production year. Also, pasture quality and quantity change throughout the year and are influenced by environment. Therefore, there commonly are times of the year where nutrient requirements are not met from the forage alone. We have long known the importance of nutrition during key development including the conception, fetal, neonatal, and weaning period. Altering nutrition during these periods can have lasting effects on health and productivity. Much of the research in ruminants examining nutritional effects on development has focused on large changes in diet, such as energy or protein restriction, rather than specific nutrients such as amino acids. Amino acids play an important role to meet requirements for lean growth but also have other physiological functions regulating metabolism and health that have important effects on development. Amino acid deficiencies during the fetal and neonatal period(s) can result in small-for-gestational age births or stunting, respectively. Diets that are deficient in protein or amino acids are also often deficient in dietary energy and other nutrients. Supplying specific amino acids (and other nutrients/energy) for absorption, signaling, and use by the animal could be an approach to help overcome negative developmental outcomes. Specific amino acids are thought to function by regulating protein synthesis, immune function, 1-C metabolism, intestinal development and health, blood flow, cellular proliferation, and behavior, to name a few. Some of the amino acids with potential for influencing developmental outcomes include leucine, arginine, glutamine, lysine, methionine, threonine, and tryptophan. Because of the varied functional roles of specific amino acids, there is great potential to develop targeted supplementation programs using amino acids to improve developmental outcomes.