Effects Of Several Feed Additives On Rumen Fermentation And Performance Of Dairy Cows

Three experiments were conducted to investigate the effects of dietary bioture, fatty acid, niacin and urease inhibitor on rumen fermentation and performance of dairy cows.Experiment 1 Three yellow cattle fixed with permanent rumen cannula were used with a 3x3 latin square design to study the effect of bioture and fatty acid on rumen pH value, ammonia concentration variation, nutrients degradability in rumen of cattle. They were allotted into treatment â…  â…¡ â…¢ feeding basal diet adding fatty acids, bioture and fatty acids adding bioture. The results show that the profiles of pH value and ammonia concentration of treatment â…  and treatment â…¡ tended to reverse. Compare with treatment â…  and treatment â…¢, treatment â…¡ increased the effective degradability of dry matter (DM) and crude protein (CP) of corn (P<0.05) significantly, decreased the effective degradability of dry matter of rice straw significantly (P<0.05). The effective degradabilities of other nutrients had no difference between three groups (P>0.05).Experiment 2 70 dairy cows were allotted randomly into two groups, i.e. control group, treatment group (adding fatty acid) to study the effects of supplementation of fatty acid on milk yield, milk fat percentage, milk protein percentage and SCC. The results show that the treatment group had the tendency of increase milk yield, milk fat percentage, milk protein percentage, but not significant (P>0.05).decreased SCC significantly (P<0.05).Experiment 3 72 dairy cows were allotted randomly into three groups, i.e. control group, treatment â…  (adding niacin) and â…¡ (adding urease inhibitor) to study the effects of supplementation of niacin and urease inhibitor on milk yield, milk fat percentage, milk protein percentage and SCC. The results show that supplemental niacin and urease inhibitor increased milk yield significantly (P<0.05), however, decreased milk fat percentage, milk protein percentage significantly (P<0.05) at the same time, supplemental urease inhibitor decreased SCC significantly(P<0.05),supplemental niacin decreased SCC significantly (P<0.05).