Abstract:

【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.

Key words: conjugated linoleic acid, oil plants seed, ruminal fermentation, lactating cows