AMINO-ACID PROFILE AND INTESTINAL DIGESTIBILITY IN DAIRY-COWS OF RUMEN-UNDEGRADABLE PROTEIN FROM VARIOUS FEEDSTUFFS
AMINO-ACID PROFILE AND INTESTINAL DIGESTIBILITY IN DAIRY-COWS OF RUMEN-UNDEGRADABLE PROTEIN FROM VARIOUS FEEDSTUFFS
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DOI：
10.3168/jds.s0022-0302(94)76982-4
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发表时间：
1994-02-01
影响因子：
3.5
通讯作者：
MEISSNER, HH
中科院分区：
文献类型：
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作者：
ERASMUS, LJ;BOTHA, PM;MEISSNER, HH
使用三头装有瘤胃插管的泌乳牛和三头装有近端十二指肠插管的奶牛来确定原位瘤胃降解对 12 种饲料的瘤胃未降解蛋白质 AA 谱的影响。使用移动袋技术测定瘤胃未降解蛋白质的肠道消化率。将每种饲料的瘤胃未降解蛋白质的可吸收 AA 谱与原始饲料和瘤胃暴露的未降解蛋白质的谱进行比较。特别是支链 AA 似乎对瘤胃中的降解具有相当的抵抗力，Phe 也是如此。 12 种饲料中有 9 种未降解蛋白质部分的赖氨酸浓度下降；蛋氨酸的降解取决于饲料。一般来说，未降解蛋白质的可吸收 AA 谱密切反映了瘤胃暴露残基的 AA 谱，这表明瘤胃降解对瘤胃后特定可吸收 AA 的提供比瘤胃后消化具有更大的影响。未降解蛋白质的肠道消化率从画眉草干草的 37.8% 到豆粕的 98% 不等；应该重新考虑大多数蛋白质系统使用的恒定消化率因子。
Three lactating cows fitted with rumen cannulas and three cows fitted with proximal duodenal cannulas were used to determine the effect of in situ rumen degradation on the AA profile of rumen-undegraded protein of 12 feedstuffs. Intestinal digestibility of rumen-undegraded protein was determined using the mobile bag technique. The absorbable AA profile of rumen-undegraded protein for each feedstuff was compared with profiles of the original feedstuff and the rumen-exposed undegraded protein. Branched-chain AA in particular seemed to be rather resistant to degradation in the rumen, as was Phe. Lysine concentrations decreased in the undegraded protein fraction in 9 of 12 feedstuffs; the degradation of Met depended on the feedstuff. The absorbable AA profiles of undegraded protein, in general, closely reflected the AA profiles of the rumen-exposed residues, which suggests that rumen degradation had a greater influence than postruminal digestion on the postruminal provision of specific absorbable AA. Intestinal digestibility of undegraded protein varied from 37.8% for Eragrostis curvula hay to 98% for soybean meal; the constant digestibility factor used by most protein systems should be reconsidered.