Abstract: [Objective] In order to explore the effects of different doses of per rumen choline chloride on milk yield, milk quality and blood biochemical indexes of periparturient cows, as well as the mechanism of action. [Method] Forty Holstein cows were randomly divided into control group, test group A, test group B and test group C. The control group was fed with normal diet, and test groups A, B and C were supplemented with 10 g/head-d, 20 g/head-d and 30 g/head-d of per rumen choline chloride on top of their diets, and milk yield, milk quality, blood glucose, total cholesterol, triglyceride and β-hydroxybutyric acid changes were detected. β-hydroxybutyric changes. [Result] Choline per rumen chloride was effective in increasing milk yield, milk fat and lactose content, promoting blood glucose recovery, lowering total cholesterol and β-hydroxybutyric acid, and improving the production performance of dairy cows. [Conclusion] The addition of 20 g/head-d per-rumen choline chloride to the diet improved the performance and blood biochemical indexes of dairy cows.

Key words: choline chloride, cow, milk yield, milk fat