Arieli A, Mabjeesh S J, Shabi Z, Bruckental I, Aharoni Y, Zamwel S, Tagari H
Department of Animal Sciences, Faculty of Agricultural, Food and Environmental Quality Sciences, Hebrew University of Jerusalem, Rehovot, Israel.
J Dairy Sci. 1998 Jul;81(7):1985-90. doi: 10.3168/jds.S0022-0302(98)75772-8.
This study analyzed the relationships among the effective degradabilities of organic matter (OM) in feedstuffs, which were assessed separately by an in situ method and a direct in vivo measurement of the rumen degradation of OM in the diets of Holstein dairy cows. For this comparison, 80 individual data points were used from studies of dairy cows that were in midlactation and that had been cannulated in the rumen and abomasum. In vivo evaluation of the true degradability of OM in the rumen was based on rare earth digesta markers. Purine N served as a microbial marker. Feed samples were incubated in the rumens of dairy cows for 3, 6, 9, 12, 24, 48, and 72 h, and effective rumen degradation was calculated from the percentage of residual OM for rumen outflow rates of 4, 6, and 8%/h. Evaluations of rumen degradability of OM by the in situ method were correlated with actual in vivo measurements of rumen degradability of OM (r2 = 0.31, 0.34, and 0.37; SE of the estimate = 4.1, 4.0, and 3.9%, respectively). We concluded that the in situ method is a useful tool for providing reliable estimates of rumen degradability of OM in dairy cows.
本研究分析了饲料中有机物（OM）有效降解率之间的关系，这些降解率分别通过原位法和对荷斯坦奶牛日粮中OM瘤胃降解的直接体内测量来评估。为了进行这种比较，使用了来自处于泌乳中期、瘤胃和真胃已插管的奶牛研究中的80个个体数据点。基于稀土消化标记物对瘤胃中OM的真降解率进行体内评估。嘌呤N用作微生物标记物。将饲料样品在奶牛瘤胃中孵育3、6、9、12、24、48和72小时，并根据瘤胃流出率为4%/小时、6%/小时和8%/小时时残留OM的百分比计算有效瘤胃降解率。通过原位法对OM瘤胃降解率的评估与OM瘤胃降解率的实际体内测量值相关（r2分别为0.31、0.34和0.37；估计标准误差分别为4.1%、4.0%和3.9%）。我们得出结论，原位法是一种有用的工具，可用于可靠估计奶牛瘤胃中OM的降解率。
