cpm-dairy 配方--以氨基酸為基礎平衡奶牛日糧

矮子 · 發(fā)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 · 發(fā)表于 2007-3-7 15:13:52

自從NRC2001出版以來，配制奶牛日糧不僅需要滿足傳統(tǒng)的“蛋白質(zhì)”需要，而且需要平衡日糧中的至少兩種首要限制性氨基酸——蛋氨酸和賴氨酸。在氨基酸供應亞模式的發(fā)展以及與之相伴的氨基酸需要的推薦量過程中采用了嚴謹?shù)姆椒?，這使得“理想蛋白”原則成為了一種更為可靠的工作體系。目前，奶牛日糧的配制在確保產(chǎn)奶量和乳成分（尤其是乳蛋白）最優(yōu)的同時，還需要保證更有效地利用日糧蛋白質(zhì)。生產(chǎn)者通過略為增加飼料成本來獲得更高價值的產(chǎn)品，從而使生產(chǎn)者有機會獲得更高的毛利（IOFC, 扣除飼料成本后的收入）。而且，在某些情況下產(chǎn)生的“潛在”效益可能會與在奶業(yè)生產(chǎn)中獲得的利潤同樣多。飼喂氨基酸平衡的日糧也可以預防某些代謝紊亂、改善能量平衡，進而改善繁殖性能。