Effects Of Fermented Chinese Herbal Medicines On Production Performance And Immune Function Of Dairy Cow In Summer

Chinese medicine has the double functions of nutrients and drugs,which can comprehensively adjust the physiological functions.The efficacy and palatability of Chinese medicine can be improved after fermented.The objective of this study was to evaluate the effects of a dietary supplement on production performance and immune function in late-lactation cows under heat stress conditions.The supplement was a fermented Chinese herbal medicines mixture consisting of eighteen herbs.Forty lactating Holstein cows?560±51.0 kg of initial BW,230±10.0 DIM,16±3.0 kg of milk per day?were randomly assigned into 4 treatment groups?10 cows/group?.Each group was fed a dietary supplemented with 0,25,50,or 100 g CHMs per cow per day.Cows were housed at high ambient temperature-humidity index?average 74.5?for an experimental period of42 days during the summer months.Results showed that:?1?Milk yield and 4%fat-corrected milk were significantly increased for CHMs compared with the group without CHMs supplements throughout the experimental period?P<0.05?.On the other hand,increasing CHMs dose demonstrated a greater milk fat and protein content?P<0.05?.From the analysis of serum physical and chemical indicators,the serum T₃ and PRL levels were increased significantly?P<0.01?;?2?The nutrient apparent digestibility of DM,EE,Ca,P,NDF,ADF and CPwere not affected by CHMs?P>0.05?,however,there was a decreasing tendency when the dietary supplemented with 100 g/d CHMs?P=0.09?;?3?The immune function was improved by CHMs under heat stress.Increasing CHMs dose demonstrated a greater lymphocyte or leukocyte count?P<0.01?,besides,the early or late apoptosis rate of the lymphocytes was decreased by CHMs supplements.The serum Bax level and mRNA expression were all down-regulated?P<0.05?,while the serum Bcl-2 level and mRNA expression were all up-regulated?P<0.05?,on the other hand,the serum IL-2 and IL-6levels,as well as IL-2 mRNA expression,increased?P<0.05?.However,the serum IL-1level tended to decrease?P=0.08?with increasing CHMs dose,and IL-1 mRNA expression was down-regulated?P<0.05?.Additionally,serum IgG levels were greater?P<0.01?for 50or 100 g/d,meanwhile,the serum HSP90 levels were all decreased?P<0.05?,which decreased by 29.6 pg/ml and 170.6 pg/ml respectively;?4?The serum CAT,SOD and T-AOC were increased significantly?P<0.05?with increasing CHMs dose,and the CAT and SOD mRNA expression were up-regulated?P<0.05?.In conclusion,CHMs supplements may relieve heat stress in dairy cows under HS,and the most suitable dose is50 g/d.