Amino acids and mammary gland development:nutritional implications for milk production and neonatal growth  

作　　者：Reza Rezaei Zhenlong Wu Yongqing Hou Fuller W.Bazer Guoyao Wu 

机构地区：[1]Department of Animal Science,Texas A&M University [2]State Key Laboratory of Animal Nutrition,China Agricultural University [3]Hubei Key Laboratory of Animal Nutritionand Feed Science,Hubei Collaborative Innovation Center for AnimalNutrition and Feed Safety,Wuhan Polytechnic University

出　　处：《Journal of Animal Science and Biotechnology》2016年第4期437-458,共22页畜牧与生物技术杂志（英文版）

基　　金：supported by Texas A&M Agri Life Research (H-8200);The Agriculture and Food Research Initiative Competitive Grant from the Animal Growth & Nutrient Utilization Program of the USDA National Institute of Food and Agriculture (2014-67015-21770);National Basic Research Program of China (2012CB126305);National Natural Science Foundation of China (31572412 and 31272450);the 111 Project (B16044);Natural Science Foundation of Hubei Province (2013CFA097 and 2013CFB325);Hubei Hundred Talent program

摘　　要：Milk is synthesized by mammary epithelial cells of lactating mammals. The synthetic capacity of the mammary gland depends largely on the number and efficiency of functional mammary epithelial cells. Structural development of the mammary gland occurs during fetal growth, prepubertal and post-pubertal periods, pregnancy, and lactation under the control of various hormones （particularly estrogen, growth hormone, insulin-like growth factor-I, progesterone, placental lactogen, and prolactin） in a species- and stage-dependent manner. Milk is essential for the growth, development, and health of neonates. Amino acids （AA）, present in both free and peptide-bound forms, are the most abundant organic nutrients in the milk of farm animals. Uptake of AA from the arterial blood of the lactating dam is the ultimate source of proteins （primarily 13-casein and a-lactalbumin） and bioactive nitrogenous metabolites in milk. Results of recent studies indicate extensive catabolism of branched-chain AA （leucine, isoleucine and valine） and arginine to synthesize glutamate, glutamine, alanine, aspartate, asparagine, proline, and polyamines. The formation of polypeptides from AA is regulated not only by hormones （e.g., prolactin, insulin and glucocorticoids） and the rate of blood flow across the lactating mammary gland, but also by concentrations of AA, lipids, glucose, vitamins and minerals in the maternal plasma, as well as the activation of the mechanistic （mammalian） target rapamycin signaling by certain AA （e.g., arginine, branched-chain AA, and glutamine）. Knowledge of AA utilization （including metabolism） by mammary epithelial cells will enhance our fundamental understanding of lactation biology and has important implications for improving the efficiency of livestock production worldwide.Milk is synthesized by mammary epithelial cells of lactating mammals. The synthetic capacity of the mammary gland depends largely on the number and efficiency of functional mammary epithelial cells. Structural development of the mammary gland occurs during fetal growth, prepubertal and post-pubertal periods, pregnancy, and lactation under the control of various hormones （particularly estrogen, growth hormone, insulin-like growth factor-I, progesterone, placental lactogen, and prolactin） in a species- and stage-dependent manner. Milk is essential for the growth, development, and health of neonates. Amino acids （AA）, present in both free and peptide-bound forms, are the most abundant organic nutrients in the milk of farm animals. Uptake of AA from the arterial blood of the lactating dam is the ultimate source of proteins （primarily 13-casein and a-lactalbumin） and bioactive nitrogenous metabolites in milk. Results of recent studies indicate extensive catabolism of branched-chain AA （leucine, isoleucine and valine） and arginine to synthesize glutamate, glutamine, alanine, aspartate, asparagine, proline, and polyamines. The formation of polypeptides from AA is regulated not only by hormones （e.g., prolactin, insulin and glucocorticoids） and the rate of blood flow across the lactating mammary gland, but also by concentrations of AA, lipids, glucose, vitamins and minerals in the maternal plasma, as well as the activation of the mechanistic （mammalian） target rapamycin signaling by certain AA （e.g., arginine, branched-chain AA, and glutamine）. Knowledge of AA utilization （including metabolism） by mammary epithelial cells will enhance our fundamental understanding of lactation biology and has important implications for improving the efficiency of livestock production worldwide.

关 键 词：Development Health LIVESTOCK Mammary gland Milk NEONATES Production SOWS 

分 类 号：S823[农业科学—畜牧学]