The effects of dietary starch and fibre on the in vitro rates of lipolysis and hydrogenation by sheep rumen digesta
The effects of dietary starch and fibre on the in vitro rates of lipolysis and hydrogenation by sheep rumen digesta
复制标题
膳食淀粉和纤维对羊瘤胃食糜体外脂肪分解和氢化率的影响
DOI：
10.1017/s0021859600055659
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
A. S. King
中科院分区：
文献类型：
--
作者：
T. Gerson;A. John;A. S. King
本工作的目的是研究改变日粮中易发酵碳水化合物和纤维的比例对绵羊瘤胃消化脂肪分解和脂肪酸氢化率的影响。使用瘤胃瘘管罗姆尼·韦瑟斯进行了三项实验。在第一个试验中，一只绵羊的瘤胃消化在高纤维日粮中加入[1-14C]亚油酸和0，0·1，0·2和0·5%的蔗糖进行体外培养。结果表明，蔗糖可使亚油酸加氢速率提高40%以上。在第二个实验中，五个瘤胃瘘罗姆尼·韦瑟斯按照拉丁方实验设计饲喂五种日粮。这些日粮中纤维比例降低(42.8-19.5%)，淀粉比例增加(12.2-35.7%)。脂肪分解和氢化速率随着纤维含量的降低而显着降低，这反映在瘤胃消化中硬脂酸和十八碳烯酸的含量上。试验三，绵羊饲喂试验一所用的高纤维日粮，瘤胃消化液分别添加0、0·15、0·45、0·75和1·50%的淀粉。脂肪分解速率增加，但添加淀粉对氢化没有影响。由此得出的结论是，短期添加能量到瘤胃消化层可以增加脂肪分解和氢化的速率。然而，长期用淀粉替代纤维会导致这些比率的降低。
SUMMARY The objective of this work was to investigate the effects of changing proportions of readily fermentable carbohydrate and fibre in the diet on the rates of lipolysis and fatty acid hydrogenation by sheep rumen digesta. Three experiments were carried out using rumen-fistulated Romney wethers. In the first experiment rumen digesta from one sheep on a high-fibre diet was incubated in vitro with [1–14C]linoleic acid and 0, 0·1, 0·2 and 0·5% sucrose. It was found that sucrose increased the rate of hydrogenation of linoleic acid by up to 40%. In the second experiment five rumen-fistulated Romney wethers were fed five diets according to a latin-square experimental design. These diets had decreasing proportions of fibre (42·8–19·5%) and increasing proportions of starch (12·2–35·7%). Lipolysis and hydrogenation rates decreased significantly with decreasing fibre content which was reflected in the amounts of stearic and octadecenoic acids in the rumen digesta. In the third experiment sheep were fed the high-fibre diet used in the first experiment and the rumen digesta incubated in the presence of 0, 0·15, 0·45, 0·75 and 1·50% starch. Lipolysis rates increased but no effect of added starch on hydrogenation was observed. It was concluded that the short-term addition of energy to the rumen digesta increases lipolysis and hydrogenation rates. However, long-term replacement of fibre by starch results in a reduction of these rates.