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 develop...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.展开更多
Protein is quantitatively the most expensive nutrient in swine diets. Hence it is imperative to understand the physiological roles played by amino acids in growth, development, lactation, reproduction, and health of p...Protein is quantitatively the most expensive nutrient in swine diets. Hence it is imperative to understand the physiological roles played by amino acids in growth, development, lactation, reproduction, and health of pigs to improve their protein nutrition and reduce the costs of pork production. Due to incomplete knowledge of amino acid biochemistry and nutrition, it was traditionally assumed that neonatal, post-weaning, growing-finishing, and gestating pigs could synthesize sufficient amounts of all ＂nutritionally nonessential amino acids＂ （NEAA） to support maximum production performance. Therefore, over the past 50 years, much emphasis has been placed on dietary requirements of nutritionally essential amino acids as building blocks for tissue proteins. However, a large body of literature shows that NEAA, particularly glutamine, glutamate, arginine and proline regulate physiological functions via cell signaling pathways, such as mammalian target of rapamycin, AMP-activated protein kinase, extracellular signal-related kinase, Jun kinase, mitogen-activated protein kinase, and NEAA-derived gaseous molecules （e.g., nitric oxide, carbon monoxide, and hydrogen sulfide）. Available evidence shows that under current feeding programs, only 70% and 55% of dietary amino acids are deposited as tissue proteins in 14-day-old sow-reared piglets and in 30-day-old pigs weaned at 21 days of age, respectively. Therefore, there is an urgent need to understand the robes and dietary requirements of NEAA in swine nutrition. This review highlights the basic biochemistry and physiology of absorption and utilization of amino acids in young pigs to enhance the efficacy of utilization of dietary protein and to minimize excretion of nitrogenous wastes from the body.展开更多
Background:Under current dietary regimens,milk production by lactating sows is insufficient to sustain the maximal growth of their piglets.As precursors of glutamate and glutamine as well as substrates and activators ...Background:Under current dietary regimens,milk production by lactating sows is insufficient to sustain the maximal growth of their piglets.As precursors of glutamate and glutamine as well as substrates and activators of protein synthesis,branched-chain amino acids(BCAAs)have great potential for enhancing milk production by sows.Methods:Thirty multiparous sows were assigned randomly into one of three groups:control(a corn-and soybean meal-based diet),the basal diet+1.535%BCAAs;and the basal diet+3.07%BCAAs.The ratio(g/g)among the supplemental L-isoleucine,L-leucine and L-valine was 1.00:2.56:1.23.Diets were made isonitrogenous by the addition of appropriate amounts of L-alanine.Lactating sows had free access to drinking water and their respective diets.The number of live-born piglets was standardized to 9 per sow at d 0 of lactation(the day of parturition).On d 3,15 and 29 of lactation,body weights and milk consumption of piglets were measured,and blood samples were obtained from sows and piglets 2 h and 1 h after feeding and nursing,respectively.Results:Feed intake did not differ among the three groups of sows.Concentrations of asparagine,glutamate,glutamine,citrulline,arginine,proline,BCAAs,and many other amino acids were greater(P<0.05)in the plasma of BCAA-supplemented sows and their piglets than those in the control group.Compared with the control,dietary supplementation with 1.535%and 3.07%BCAAs increased(P<0.05)concentrations of free and protein-bound BCAAs,glutamate plus glutamine,aspartate plus asparagine,and many other amino acids in milk;milk production by 14%and 21%,respectively;daily weight gains of piglets by 19%and 28%,respectively,while reducing preweaning mortality rates by 50%and 70%,respectively.Conclusion:Dietary supplementation with up to 3.07%BCAAs enhanced milk production by lactating sows,and the growth and survival of their piglets.展开更多
This study determined effects of birth weights （0.70 to 1.09, 1.10 to 1.49, 1.50 to 1.89, and ≥ 1.90 kg） on the efficiency of milk utilization for growth in sow-reared piglets. One-hundred-sixty piglets from 18 mul...This study determined effects of birth weights （0.70 to 1.09, 1.10 to 1.49, 1.50 to 1.89, and ≥ 1.90 kg） on the efficiency of milk utilization for growth in sow-reared piglets. One-hundred-sixty piglets from 18 multiparous sows （ Landrace × Large White） were individually weighed immediately after birth （ day 0） and at 7-day intervals for 35 days. Milk consumption of piglets was determined weekly using the weigh-suckle-weigh method. Deaths of piglets were recorded daily. Piglets with the lightest birth weight had the highest incidence of mortality. Birth weights between 0.70 and 1.89 kg were positively as- sociated with average dally gains （ADG, g/day ） during the suckling period （ P 〈 0.01 ）. Compared with piglets having birth weights of 1.50 to 1.89 kg, birth weights ≥ 1.90 kg did not confer any additional benefit on preweaning survival or ADG. Colostrum or milk consumption per kilogram of body weight among low-, normal-, and large-birth-weight piglets did not differ in the first week. At days 14 to 35, milk consumption of piglets （ g/kg BW/day ） increased （e 〈 0. 01 ） but the ratio of gain to milk consumption decreased （ P 〈 0.01 ） progressively, as their birth weights increased from 0.70 to ≥1.90 kg. Additionally, surviving low-birth-weight piglets had a higher relative growth rate （%/day ） than normal-and large-birth- weight piglets. Based on these novel findings, it is imperative that great efforts be made to improve the survival of low-birth-weight piglets so as to increase the efficiency of nutrient utilization by both lactating sows and suckling piglets.展开更多
Interoperability is the ability of systems to provide services to and accept services from other systems,and to use the services exchanged so as to operate together in a more effective manner.The fact that interoperab...Interoperability is the ability of systems to provide services to and accept services from other systems,and to use the services exchanged so as to operate together in a more effective manner.The fact that interoperability can be improved means that the metrics for measuring interoperability can be defined.For the purpose of measuring the interoperability between systems,an interoperability assessment model is required.This paper deals with the existing interoperability assessment models.A comparative analysis among these models is provided to evaluate the similarities and differences in their philosophy and implementation.The analysis yields a set of recommendations for any party that is open to the idea of creating or improving an interoperability assessment model.展开更多
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)+4 种基金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
文摘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.
基金supported by National Research Initiative Competitive Grants from the Animal Reproduction Program(2008-35203-19120)Animal Growth&Nutrient Utilization Program(2008-35206-18764)of the USDA National Institute of Food and Agriculture+6 种基金AHA(10GRNT4480020)Texas A&M AgriLife Research(H-8200)the National Basic Research Program of China(2013CB127302)the National Natural Science Foundation of China(30810103902,30972156,31172217,31272450,and 31272451)China Postdoctoral Science Foundation(2012T50163)Chinese Universities Scientific Funds(2012RC024)the Thousand-People Talent program at China Agricultural University
文摘Protein is quantitatively the most expensive nutrient in swine diets. Hence it is imperative to understand the physiological roles played by amino acids in growth, development, lactation, reproduction, and health of pigs to improve their protein nutrition and reduce the costs of pork production. Due to incomplete knowledge of amino acid biochemistry and nutrition, it was traditionally assumed that neonatal, post-weaning, growing-finishing, and gestating pigs could synthesize sufficient amounts of all ＂nutritionally nonessential amino acids＂ （NEAA） to support maximum production performance. Therefore, over the past 50 years, much emphasis has been placed on dietary requirements of nutritionally essential amino acids as building blocks for tissue proteins. However, a large body of literature shows that NEAA, particularly glutamine, glutamate, arginine and proline regulate physiological functions via cell signaling pathways, such as mammalian target of rapamycin, AMP-activated protein kinase, extracellular signal-related kinase, Jun kinase, mitogen-activated protein kinase, and NEAA-derived gaseous molecules （e.g., nitric oxide, carbon monoxide, and hydrogen sulfide）. Available evidence shows that under current feeding programs, only 70% and 55% of dietary amino acids are deposited as tissue proteins in 14-day-old sow-reared piglets and in 30-day-old pigs weaned at 21 days of age, respectively. Therefore, there is an urgent need to understand the robes and dietary requirements of NEAA in swine nutrition. This review highlights the basic biochemistry and physiology of absorption and utilization of amino acids in young pigs to enhance the efficacy of utilization of dietary protein and to minimize excretion of nitrogenous wastes from the body.
基金supported by Texas A&M AgriLife Research Hatch project(H8200)Ajinomoto Co.,Tokyo,Japan.
文摘Background:Under current dietary regimens,milk production by lactating sows is insufficient to sustain the maximal growth of their piglets.As precursors of glutamate and glutamine as well as substrates and activators of protein synthesis,branched-chain amino acids(BCAAs)have great potential for enhancing milk production by sows.Methods:Thirty multiparous sows were assigned randomly into one of three groups:control(a corn-and soybean meal-based diet),the basal diet+1.535%BCAAs;and the basal diet+3.07%BCAAs.The ratio(g/g)among the supplemental L-isoleucine,L-leucine and L-valine was 1.00:2.56:1.23.Diets were made isonitrogenous by the addition of appropriate amounts of L-alanine.Lactating sows had free access to drinking water and their respective diets.The number of live-born piglets was standardized to 9 per sow at d 0 of lactation(the day of parturition).On d 3,15 and 29 of lactation,body weights and milk consumption of piglets were measured,and blood samples were obtained from sows and piglets 2 h and 1 h after feeding and nursing,respectively.Results:Feed intake did not differ among the three groups of sows.Concentrations of asparagine,glutamate,glutamine,citrulline,arginine,proline,BCAAs,and many other amino acids were greater(P<0.05)in the plasma of BCAA-supplemented sows and their piglets than those in the control group.Compared with the control,dietary supplementation with 1.535%and 3.07%BCAAs increased(P<0.05)concentrations of free and protein-bound BCAAs,glutamate plus glutamine,aspartate plus asparagine,and many other amino acids in milk;milk production by 14%and 21%,respectively;daily weight gains of piglets by 19%and 28%,respectively,while reducing preweaning mortality rates by 50%and 70%,respectively.Conclusion:Dietary supplementation with up to 3.07%BCAAs enhanced milk production by lactating sows,and the growth and survival of their piglets.
基金supported by funds from Agriculture and Food Research Initiative Competitive Grants no.2008-35206-187642008-35203-19120 from the USDA National Institute of Food and AgricultureTexas AgriLife Research Hatch project (H-8200), and Texas A&M University (College Station, Texas, USA)
文摘This study determined effects of birth weights （0.70 to 1.09, 1.10 to 1.49, 1.50 to 1.89, and ≥ 1.90 kg） on the efficiency of milk utilization for growth in sow-reared piglets. One-hundred-sixty piglets from 18 multiparous sows （ Landrace × Large White） were individually weighed immediately after birth （ day 0） and at 7-day intervals for 35 days. Milk consumption of piglets was determined weekly using the weigh-suckle-weigh method. Deaths of piglets were recorded daily. Piglets with the lightest birth weight had the highest incidence of mortality. Birth weights between 0.70 and 1.89 kg were positively as- sociated with average dally gains （ADG, g/day ） during the suckling period （ P 〈 0.01 ）. Compared with piglets having birth weights of 1.50 to 1.89 kg, birth weights ≥ 1.90 kg did not confer any additional benefit on preweaning survival or ADG. Colostrum or milk consumption per kilogram of body weight among low-, normal-, and large-birth-weight piglets did not differ in the first week. At days 14 to 35, milk consumption of piglets （ g/kg BW/day ） increased （e 〈 0. 01 ） but the ratio of gain to milk consumption decreased （ P 〈 0.01 ） progressively, as their birth weights increased from 0.70 to ≥1.90 kg. Additionally, surviving low-birth-weight piglets had a higher relative growth rate （%/day ） than normal-and large-birth- weight piglets. Based on these novel findings, it is imperative that great efforts be made to improve the survival of low-birth-weight piglets so as to increase the efficiency of nutrient utilization by both lactating sows and suckling piglets.
基金Project (No.RG055-11ICT) supported by the University of Malaya Research Grant (UMRG),Malaysia
文摘Interoperability is the ability of systems to provide services to and accept services from other systems,and to use the services exchanged so as to operate together in a more effective manner.The fact that interoperability can be improved means that the metrics for measuring interoperability can be defined.For the purpose of measuring the interoperability between systems,an interoperability assessment model is required.This paper deals with the existing interoperability assessment models.A comparative analysis among these models is provided to evaluate the similarities and differences in their philosophy and implementation.The analysis yields a set of recommendations for any party that is open to the idea of creating or improving an interoperability assessment model.
