不同油料籽实对奶牛瘤胃液、血浆脂肪酸组成及乳脂CLA含量的影响

 【目的】研究不同脂肪酸构成的油料籽实对奶牛瘤胃液和血浆中脂肪酸的组成及乳脂CLA含量的影响，初步探讨乳脂CLA合成机制，为改善牛奶脂肪酸构成，提高乳脂中CLA含量寻找合适途径。【方法】以3头装有永久性瘤胃瘘管的经产荷斯坦奶牛为试验动物，采用3×3拉丁方设计，在日粮中添加不同油料籽实（葵花籽、亚麻籽、菜籽），3种日粮的粗脂肪含量基本相同，测定采食后不同时间点瘤胃液、血浆及乳脂中脂肪酸含量。【结果】葵花籽组奶牛乳脂中CLA、t11-C18﹕1、PUFA及LCFA比例均显著高于菜籽组和亚麻籽组（P＜0.05）;葵花籽组奶牛血浆中t11-C18﹕1的比例显著高于菜籽组和亚麻籽组（P＜0.05）;瘤胃液中各种脂肪酸含量在3组之间差异不显著（P＞0.05），随采食后时间的延长，饱和脂肪酸含量逐渐增加，不饱和脂肪酸含量逐渐减少，不同时间点瘤胃液中CLA的比例均较低;瘤胃液、血浆中的t11-C18﹕1含量对乳脂中CLA含量的决定系数（R2）分别为0.841和0.766。【结论】富含亚油酸的葵花籽在优化奶牛乳脂肪酸构成、提高CLA含量方面效果最好。

Effects of Seeds of Different Oil Plants on Fatty Acid in Ruminal Fluid, Blood Plasma and Milk CLA of Lactating Cows

【Objective】 Three multiparous Chinese Holstein lactating cows with permanent rumen cannula were used to study the effects of adding different kinds of seeds of oil plants on fatty acid in ruminal fluid, blood plasma and milk CLA of lactating cows.【Method】 Experimental design used a 3×3 Latin square design (sunflower seed group, flax seed group and rape seed group).【Result】The proportion of CLA, t11-C18﹕1, PUFA and LCFA in milk fat in sunflowerseed group was significantly improved than that in flaxseed group and rapeseed group when adding different kinds of oil plants seed (sunflower seed, flax seed and rape seed) in the diets (P＜0.05). The proportion of t11-C18:1 in blood plasma in sunflower seed group was significantly improved than that in flax seed group and rape seed group (P＜0.05). There was an insignificant difference among the averages in three mensuration for all kinds of fatty acids in ruminal fluid after intaking the diets supplied different plant oil (P＞0.05), but the proportion of the saturation fatty acids gradually increased, and the proportion of unsaturated fatty acids gradually decreased, the proportion of CLA in ruminal fluid was always low in different times. The coefficient of determination of t11-C18﹕1 in ruminal fluid and blood plasma for CLA in milk fat from cows were 0.841and 0.766, respectively.【Conclusion】The sunflower seed is the best in improving the milk CLA and the composition of fatty acid in lactating cows.