Proportions of volatile fatty acids in relation to the chemical composition of feeds based on grass silage
Proportions of volatile fatty acids in relation to the chemical composition of feeds based on grass silage
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DOI：
10.3168/jds.s0022-0302(98)75696-6
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发表时间：
1998-05-01
影响因子：
3.5
通讯作者：
Horgan, G
中科院分区：
文献类型：
--
作者：
Friggens, NC;Oldham, JD;Horgan, G
该实验旨在量化各种饲料中饲料化学成分与瘤胃挥发性脂肪酸 (VFA) 比例之间的关系。在一项使用 11 只瘤胃插管羊的实验中，在基于青贮饲料的日粮中以三种不同的添加比例饲喂 16 种测试饲料。实验共 17 个周期，每个周期 14 d。每个时期的第 13 和 14 天，每 24 小时采集 8 个瘤胃样本，从中得出 VFA 的平均每日比例。增加试验饲料在总饲料中的比例对 VFA 比例的影响是显着的。通过主成分回归，观察到的 VFA 比例与总饲料的化学成分相关。在这些回归中纳入提供的饲料量以及测试饲料与总饲料的比率并没有提高其精度；这些条款并不重要。回归中的显着项是粗蛋白、淀粉、糖和纤维素（按差值计算）。乙酸盐、丙酸盐和丁酸盐（摩尔比例）与饲料成分之间的回归得到的 R-2 值分别为 77.5%、68.0% 和 87.3%。这些回归为根据草青贮饲料中的饲料化学预测 VFA 的摩尔比例提供了明显可靠的基础。
This experiment was designed to quantify the relationships between feed chemistry and the proportions of rumen volatile fatty acids (VFA) across a wide range of feedstuffs. In an experiment using 11 rumen-cannulated sheep, 16 test feeds were fed at three different inclusion rates in rations that were based on grass silage. The 17 periods of the experiment were each 14 d long. Eight rumen samples were taken every 24 h on d 13 and 14 of each period from which the mean daily proportions of VFA were derived. The effects of an increase in the proportion of test feed in the total feed on proportions of VFA were significant. The observed proportions of VFA were related to the chemical composition of the total feed by principal component regression. The inclusion of the amount of feed offered and the ratio of test feed to total feed in these regressions did not improve their precision; these terms were not significant. The significant terms in the regressions were crude protein, starch, sugar, and cellulose (calculated by difference). The R-2 values achieved for the regressions between acetate, propionate, and butyrate (molar proportions) and feed composition were 77.5, 68.0, and 87.3%, respectively. These regressions provided an apparently robust basis for predicting molar proportions of VFA from feed chemistry in feeds based on grass silage.