Effects Of Compound Chinese Herbal Additives On Relieving Heat Stress On Performance Of Low-Yielding Dairy Cows

With global warming changes,heat stress has become an important production problem affecting dairy cattle farming on a large scale.The immune system,endocrine levels,energy metabolism and utilization,and production performance of the body are all affected due to the high temperature and humidity in cows.The aim of this paper is to investigate the alleviating effect of compound supplements from Chinese herbal medicine on heat stress-induced performance of low-yielding dairy cows.A total of 30 low-yielding Holstein cows were selected as research subjects and randomly divided into three groups:the control group（CK）,the vitamin group（VC）and the group with Chinese herbal medicine supplements（CT）,10 cows in each group.The control group was fed a basic ration,the vitamin group received 2 g of soluble vitamin C powder per head per day based on the basic ration,and the Chinese herbal medicine group received 90 g of Chinese herbal supplements per head per day based on the basic rations.The experimental period is 42days in total,and the temperature and humidity of the barn environment,the rectal temperature of the cows,and the milk production are recorded regularly every day;in addition,dynamic changes in oxidative capacity,heat shock protein activity,milk composition index,fecal crude protein,crude fat,and moisture are recorded on the 1st,24th,and 42nd days.Disease incidence was also counted in the experimental beef herd.The results show:（1）During the experimental period,the temperature and humidity index in the dairy cow barns ranged from 75.59 to 80.27,and the average temperature and humidity index for the whole day was 77.78,indicating that the cows were in a state of heat stress during the experimental period.（2）Compared with the CK group,the body temperature of cows in the VC and CT groups decreased;compared with the VC group,the body temperature of cows in the CT group decreased more significantly.（3）On the 24th day of experiment,the serum contents ALB and GLOB of group CT were significantly increased（P<0.05）and the contents AST,BUN and TG were significantly decreased（P<0.05）compared to group CK;the VC group of GLU was significantly increased（P<0.05）;on the 42nd day,compared with the CK group,the contents of TP,A/G ratio,GLU,ALB and GLOB in the CT group were significantly increased（P<0.01）,AST,ALT The contents of ALB,GLOB and TP in the VC group were significantly increased（P<0.01）.（4）On the 24th and 42nd day of the experiment,compared with the CK group,the serum K⁺and Cl^-contents of the CT group were extremely significantly decreased（P<0.01）,and the serum Na⁺,t Ca²⁺,i Ca²⁺,n Ca²⁺and Ca²⁺contents were extremely significantly increased（P<0.0）;the trend of serum changes in the VC group was basically the same as that in the CT group（P<0.05）.（5）On the 24th day of the experiment,compared with the CK group,the contents of SOD,GPX and T-AOC in the CT group were significantly increased（P<0.01）,and the contents of SOD and T-AOC in the VC group were significantly higher than those in the CK group（P<0.05 or P<0.01）.On the 42nd day of the experiment,the serum MDA levels in the CT and VC groups were extremely significantly decreased（P<0.01）,and the SOD,T-AOC,and GPX levels were extremely significantly increased（P<0.05 or P<0.01）.The activity of HSP70 decreased significantly（P<0.05 or P<0.01）,and this trend changed with the increase of heat stress time.（6）Compared with the control group,the lactose rate,milk fat rate,milk protein rate,and total milk solids in the CT group and the VC group were significantly increased（P<0.05 or P<0.01）,somatic cell count,milk urea nitrogen,and feces The proportion of fat was significantly reduced（P<0.05 or P<0.01）.（7）During the test,the incidence rate of CK cows was 50%,that of VC cows was33.3%,and that of cows in the compound Chinese herbal medicine group was 0.It shows that the compound Chinese herbal medicine supplements used in this experiment can effectively improve the disease of dairy cows.（8）In the correlation analysis,it was found that in the CK group,temperature,humidity,THI had a significant correlation with all the indicators in the cow body;in the VC group,there was a significant correlation with TG,ALB,GLOB,K⁺,Cl^-,SOD,GPX,T-AOC showed a significant correlation;in the CT group,there was a significant correlation with AST,TP,ALB,K⁺,Cl^-,T-AOC which further proved that adding vitamin C and Chinese herbal medicine can improve many indicators of dairy cows and alleviate heat stress in dairy cows.In summary,VC and compound Chinese herbal medicine additives can alleviate the impact of heat stress on the production performance of cows,causing blood electrolyte disorders,and subsequently triggering oxidative stress in the body,leading to liver and kidney dysfunction,and easily leading to diseases.The effect of compound Chinese herbal medicine is more obvious.