Effects of Biotin on Lactation Performance,Nutrient Digestion and Rumen Fermentation of Holstein Dairy Cows
This experiment was conducted to investigate the effects of biotin on lactation performance,nutrient digestion and rumen fermentation of Holstein dairy cows.Forty-eight Holstein dairy cows with similar milk yield,parity and lactation days were randomly divided into 4 groups which supplemented with 0(control group),10,20 and 30 mg/d biotin in the basal diet,respectively,with 12 cows in each group.The pre-trial period lasted for 20 days and the experimental period lasted for 60 days.During the trial,the daily feed intake and milk production of each cow were recorded,and the samples of diet,milk,feces,rumen fluid and blood were collected to determine the milk composition content,nutrient apparent digestibility,rumen fermentation parameters and blood indexes.The results showed that,with the increase of biotin supplemental level,the dry matter intake of dairy cows had no significant change(P＞0.05);the milk yield,milk fat and milk protein yields,milk fat content and feed efficiency were linearly increased(P＜0.05);the apparent digestibility of each nutrient was linearly increased(P＜0.05);the rumen pH and acetate to propionate ratio were linearly de-creased(P＜0.05);the contents of total volatile fatty acids,acetate and propionate in rumen were linearly in-creased(P＜0.05);the numbers of Ruminobacter amylophilus,Butyrivibrio fibrisolvens,Ruminococcus al-bus,Ruminococcus flavefaciens,total bacteria and total fungi in rumen were linearly increased(P＜0.05);and the contents of glucose,triglyceride and insulin in serum had no significant changes(P＞0.05),the contents of non-esterification fatty acid and β-hydroxybutyric acid in serum were linearly decreased(P＜0.05),and the bi-otin content in serum was linearly increased(P＜0.05).In conclusion,biotin supplementation can improve lac-tation performance,nutrient digestion and rumen fermentation of dairy cows,and the recommended biotin sup-plemental level is 20 mg/d.[Chinese Journal of Animal Nutrition,2024,36(1):352-359]
万方数据
维普
