包被叶酸或包被硫酸锌对奶牛生产性能和瘤胃发酵的影响OA

The study evaluated the effects of coated folic acid(CFA)or coated zinc sulfate(CZS)on lactation performance,nutrient digestion,rumen fermentation and antioxidant indicator in dairy cows.Forty-eight mid-lactation Chinese Holstein dairy cows were selected and assigned in a randomized block design to 4 groups:control group without supplementation,CFA,CZS groups and CFZ group with supplementation of CFA 6 g/d,CZS 200 mg/d and CFA 6 g/d+CZS 200 mg/d,respectively.The experiment period was 80 days with 20 days for adaptation.The results showed that supplementation with CFA or CZS increased fat-corrected milk(FCM)yield,milk fat yield,feed efficiency(FE),rumen total volatile fatty acids(TVFA)con-tent,acetate molar proportion and acetate to propionate ratio,and blood total protein,albumin,superoxide dismutase(SOD)and glutathione peroxidase(GSH-Px)(P<0.05).Dietary supplementation of CFA increased the digestibility of dry matter(DM),organic matter,crude protein,neutral deter-gent fiber(NDF)and acid detergent fiber,and blood 5-methyltetrahydrofolate level(P<0.05).Dietary supplementation of CZS increased the digestibility of DM and NDF,and blood alkaline phosphatase activity(P<0.05).The significant interaction between CFA and CZS was observed on FE,rumen TVFA content,blood SOD and GSH-Px activities(P<0.05).The results indicate that supplementation of CFA or CZS increase FCM yield,and the combined addition of CFA and CZS is more efficient in improv-ing FE,rumen fermentation and antioxidant status in dairy cows.