اثرات تغذيه اي كولين بر عملكرد توليدي و برخي فراسنجه هاي خوني گاوهاي هلشتاين شيرده

Nutritional effects of choline on productive performance and some blood metabolites of lactating Holstein dairy cow

Nutritional effects of rumen-protected and unprotected choline on milk yield, milk composition and some blood metabolites of lactating Holstein dairy cow investigated in a balanced change over design with eight dairy cows, four treatments and four periods of 21 days. Experimental treatments includc: 1-basal diet or control (without choline), 2-basal diet + 50 g/per day unprotected choline, 3- basal diet + 25 g/per day rumen-protected choline and 4-basal diet + 50 g/per day rumen-protected choline. The cows were fed individually ad lib. Twice daily. Milk and blood samples were taken at the two and last day of each period respectively. Rumen-protected choline (50 g/per day) increased dry matter intake and milk yield. Fat corrected milk and fat yield were significantly higher in rumen- protected choline (50 g/per day) than unprotected choline and control group. The concentration of protein, lactose and solid non fat in milk were not affected by the treatments. Rumen-protected choline significantly increased milk fat percentage compared to unprotected choline. There were no significant differences in blood glucose, cholesterol, triglyceride and blood urea nitrogen concentration between treatments. However some favorable effects of the choline are seen in this experiment, but more investigations are needed for practical advices.