cpm-dairy 配方--以氨基酸为基础平衡奶牛日粮

矮子 · 发表于 2007-3-7 15:06:27

Summary
Amino acid supply to the mammary gland directly affects milk protein synthesis and milk volume and indirectly impacts productivity by affecting metabolism and immune function. The complexity of balancing rations on the basis of amino acids requires computer models. CPM-Dairy calculates amino acid requirements by a factorial method and by an ideal protein method. Balancing rations on the basis of amino begins with optimizing production of microbial protein in the rumen. Next, rumen outputs of amino acids are complemented with dietary sources that escape ruminal fermentation. Feeds with high concentrations of methionine and lysine in metabolizable protein are helpful but single sources of rumen-protected amino acids are usually needed.

矮子 · 发表于 2007-3-7 15:13:52

自从NRC2001出版以来，配制奶牛日粮不仅需要满足传统的“蛋白质”需要，而且需要平衡日粮中的至少两种首要限制性氨基酸——蛋氨酸和赖氨酸。在氨基酸供应亚模式的发展以及与之相伴的氨基酸需要的推荐量过程中采用了严谨的方法，这使得“理想蛋白”原则成为了一种更为可靠的工作体系。目前，奶牛日粮的配制在确保产奶量和乳成分（尤其是乳蛋白）最优的同时，还需要保证更有效地利用日粮蛋白质。生产者通过略为增加饲料成本来获得更高价值的产品，从而使生产者有机会获得更高的毛利（IOFC, 扣除饲料成本后的收入）。而且，在某些情况下产生的“潜在”效益可能会与在奶业生产中获得的利润同样多。饲喂氨基酸平衡的日粮也可以预防某些代谢紊乱、改善能量平衡，进而改善繁殖性能。