The Effects Of Organic Trace Minerals On Production Performance And Serum Biochemical Indexes In Dairy Cows

The aim of this study was to evaluate the effects of organic trace minerals on production performance and serum biochemical indexes in dairy cows by adding organic trace minerals into the basal diet,and to provide the basis for the using of organic trace minerals in dairy cows production.Section one:The effects of organic trace minerals on production performance in dairy cows were studied in the experiment.60 dairy cows with similar age,parity,milk yield and lactating time were randomly divided into the control group and the treatment group(30 cows of each group).The cows in treatment group fed the organic trace minerals 2 times a day under the same feeding-and-management condition with the control group.Compared with the control group,the levels of milk yield,milk protein and milk fat increased in the treatment group(P<0.05),the level of milk lactose decreased slightly(P>0.05),the contents of total solids and somatic cell count declined,and the level of milk urea nitrogen decreased significantly(P<0.05).The body condition score and the hardness of hoof in dairy cows were improved in the treatment group by organic trace minerals(P<0.05).Section two:The effects of organic trace minerals on serum biochemical indexes in dairy cows were studied in the experiment.The test design and test material were same with the section one.Organic trace minerals changed the levels of superoxide dismutase(SOD),malondialdehyde(MDA)and glutathion peroxidase(GSH-Px),but had no significant difference with those in the control group(P>0.05).Compared with the control group,the content of total antioxidant capacity(T-AOC)in treatment group increased significantly(P<0.05).The levels of total cholesterol,triglyceride,high-density lipoprotein(HDL)and low density lipoprotein(LDL)tended to decline(P>0.05).But,the levels of some ions tended to increase(P>0.05).Section three:This experiment was conducted to study whether feeding organic trace elements to cows enhances their production performance,blood parameters during summer heat stress.Thirty lactating Holstein cows with similar age,parity,milk production date and milk yield were randomly divided into 2 groups:the control group which added 120g/day distillers dried gains with soluble(DDGS)to total mixed ration(TMR),and experimental groups that added 15g/day organic mineral elements and 105g/day DDGS to TMR for 60 days.The result showed that feeding organic trace elements to cows decreased rectal temperature(P<0.05).The milk yield had a trend to increase(P>0.05).Immunoglobulin G,total antioxidant capacity,and other index between 2 groups had no significant difference(P>0.05),These results indicate that supplementing 15g/day organic mineral elements and 105g/day DDGS to the diet of dairy cows increases their milk performance,improves their antioxidant capacity and helps the cow relieve from heat stress,In conclusion,supplementing dairy cows with organic mineral elements generated the most positive influence on milk performance and reduction in heat stress.