Effects Of Rumen-bypass Nicotinic Acid And Choline On Performance Of Dairy Cows

In this study,300 adult cows were randomly divided into 3 groups with 100 cows in each group after 7 days of adaptation.In Test Group 1,Ruminal Choline(56g/Head/day)was added,in Test Group 2,ruminal Nicotinic Acid(20g/head/day)was added,and in Test Group 3,ruminal Nicotinic Acid(20g/head/day)+Rumi nal Choline(56g/Head/day)was added,the effects of rumen-passed nicotinic acid and choline on the performance of dairy cows were studied.The results were as follows:Experiment 1:The effects of rumen-bypass nicotinic acid and rumen-bypass Choline on milk production efficiency and morbidity of dairy cows.The dry matter intake of the choline group was significantly lower than that of the nicotinic acid group and the nicotinic acid+Choline Group(p=0.045)However,there was no significant difference in dry matter intake among the three treatment groups in the new birth stage P>0.05;Compared with nicotinic acid group and nicotinic acid+Choline group,the intake of dry matter in puerperal cattle was significantly lower(P≪0.01).The dry matter intake of dairy cows in the Choline Group was significantly higher than that of dairy cows in the nicotinic acid + Choline Group(P≪0.01).Compared with nicotinic acid group and nicotinic acid+Choline Group,the milk yield of choline group increased 6.99%(P<0.05)and 0.63%(P≪0.05),respectively.In the milk production efficiency,the choline group and the Nicotinic acid+choline group increased slightly,and were significantly higher than the nicotinic acid group.The incidence of Ketosis in the Choline Group was higher than that in the nicotinic acid group and the nicotinic acid+Choline Group,and the difference was significant(P≪0.05).There was no significant diffeence between nicotinic acid group and nicotinic acid+Choline Group(P>0.05).Experiment 2:The effects of rumen-bypass nicotinic acid and rumen-bypass choline on milk composition of dairy cows.There was no significant difference in milk fat and milk dry matter between the three groups(P>0.05),milk urea nitrogen and milk proteta in dacin group were significantly higher than those in Choline Group and Niacin+Choline Group(P≪0.05),the Somatic Cell Count and total bacterial count in milk were significantly lower than those in the other two groups(P≪0.05).The results showed that niacin group could increase milk urea nitrogen and milk protein,decrease milk somatic cell count and total bacterial count.Experiment 3:The effects of rumen-bypass nicotinic acid and rumen-bypass Choline on the reproductive performance of dairy cows.There were significant differences in reproductive performance among the three groups,among which the average days of empty pregnant,the Times of mating and the conception rate of estrus in the Choline Group were significantly better than those in the nicotinic acid group and nicotinic acid+Choline Group(P≪0.05)However,there was no significant difference in the first mating time and conception rate among the three groups(P>0.05),and the body condition score of the perinatal cattle in the choline group was significantly lower than that of the choline + Nicotinic acid group and NICOTINIC ACID group(P≪0.05).The results showed that the Choline Group could promote the reproductive performance.Experiment 4:The effects of rumen-bypass nicotinic acid and rumen-bypass choline on blood parameters of dairy cows.There were significant differences in insulin(INS),cholesterol(CH),non-esterified fatty acids(NEFA),high-density Lipoprotein,Low-density Lipoprotein and triglyceride among the three groups.The levels of insulin(INS),cholesterol(CH)and non-esterified fatty acids(NEFA)in niacin group and NIACIN+Choline Group were significantly higher than those in Choline Group(P≪0.05).There was no significant difference between niacin group and NIACIN+Choline Group(P>0.05)The Low-density Lipoprotein and triglyceride in Niacin group were significantly lower than those in the other two groups(P≪0.05).In conclusion,Dietary Choline Supplementation was superior to the other two groups in performance,but Niacin supplementation had a tendency to prevent ketosis.