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The study on the kinetic analysis of arginine metabolism for healthy growth of young calves

犊牛健康生长精氨酸代谢动力学分析研究

基本信息

批准号：
18580270
负责人：
OBITSU Taketo
金额：
$ 2.11万
依托单位：
Hiroshima University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2006
资助国家：
日本
起止时间：
2006 至 2007
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-18580270/
关键词：
Arginine Urea Amino acid metabolism Stable isotopes Calves クレアチン一酸化窒素

项目摘要

It is important to rear healthy calves because consumers request safety agricultural products. Arginine, which is one of amino acids constituting body protein, has multiple functions in animal nutrition and health. Arginine is used as substrates not only for body protein synthesis but also for the production of nitrogen oxide that promotes immune response. Thus, quantification of arginine metabolism in calves is important to establish the management system for healthy growth of calves.Urea production dramatically increases after weaning in calves, because of increased ammonia absorption from the rumen followed by increased dry matter intake and rumen development. Arginine is a substrate for urea production in the liver, so that increased urea production may facilitate the demands of plasma arginine for the urea synthesis. This additional demand of arginine would decrease its supply for body protein synthesis and other important functions. The objective of this study was to investigate the effect of weaning on anginine flux for urea production in young calves.Holstein calves were fed only milk replacer till 4 weeks of age, then began to offer the concentrate diets and hay with milk replacer till 7 weeks. After weaning at 7 weeks, calves were fed only solid feeds. Calves were fed diets to satisfy the energy and protein requirements for growth rate of 0.7 kg/d. At 4 and 14 or 15 weeks, calves were infused with [guanido ^<15>N_2]arginine and [^<13>C]urea into the jugular vein to measure the flux of plasma arginine and the rate of conversion of guanido-N of plasma arginine to urea synthesized in the liver.Urea production increased after weaning, but total plasma arginine flux decreased. The rate of plasma arginine converted to urea was not changed after weaning, but the proportion of plasma arginine used for urea production to total arginine flux was increased.

由于消费者对安全农产品的需求，饲养健康的犊牛非常重要。精氨酸是构成机体蛋白质的氨基酸之一，在动物营养和保健方面具有多种功能。精氨酸不仅用作身体蛋白质合成的底物，而且还用于产生促进免疫反应的氮氧化物。因此，定量测定犊牛精氨酸代谢对建立犊牛健康生长管理体系具有重要意义。犊牛断奶后尿素产量显著增加，这是由于瘤胃氨吸收增加，干物质采食量增加，瘤胃发育加快。精氨酸是肝脏中尿素产生的底物，因此尿素产生的增加可促进尿素合成对血浆精氨酸的需求。精氨酸的这种额外需求将减少其对身体蛋白质合成和其他重要功能的供应。本试验以荷斯坦犊牛为研究对象，在4周龄前只饲喂乳蛋白消化剂，7周龄后开始饲喂精料和干草加乳蛋白消化剂，研究断奶对犊牛尿素生成的心绞痛流量的影响。7周断奶后，小牛只喂固体饲料。饲喂犊牛饲料以满足0.7 kg/d生长速率的能量和蛋白质需求。在4、14或15周龄时，经颈静脉分别注入[胍基-<15>N_2]精氨酸和[胍基-<13>C]尿素，测定血浆精氨酸流量和血浆精氨酸胍基-N转化为肝脏合成尿素的速率。断奶后血浆精氨酸转化为尿素的速率没有变化，但用于尿素生产的血浆精氨酸占总精氨酸流量的比例增加。