Effects Of VE And Se On Oxidative Stress, Immunosuppression, Performance And Health In Dairy Cows

VE and Se,as important antioxidants and immune enhancers,can improve the oxidative stress and immunosuppression,reduce the severity of important economic diseases such as mastitis and metritis in dairy cows.Due to the lack of VE and Se is closely related to the occurrence of postpartum inflammatory diseases in perinatal dairy cows,and the lack of practical and rapid monitoring means of vitamins and trace elements in intensive cattle farms,the current subclinical VE and Se deficiency has gradually become one of the main nutritional and metabolic diseases that harm the health of dairy cows.Therefore,this study carried out two trials for investigation of VE deficiency and Se deficiency in dairy cows during perinatal and early lactation,and effects of VE and Se supplementation on oxidative stress,immunosuppression,production performance and disease in dairy cows to clarify effects of VE and Se on oxidative stress,immune suppression,performance,health and economic benefits of dairy cows during perinatal and early lactation,and to provide scientific basis for controlling VE and Se deficiency and maintaining health of dairy cows in the future.Test 1.Investigation of VE deficiency and Se deficiency in dairy cows during perinatal and early lactation.This experiment was carried out on two intensive cattle farms in Heilongjiang Province.Ten cows were randomly selected at 10 days before calving,the day of calving,10-20 days and 50-60 days after calving respectively,and a total of 80 dairy cows were selected from the two dairy farms.According to the significance analysis,Pearson correlation analysis and risk early warning assessment analysis of the production data and blood biochemical indexes of experimental cows,the results showed that:(1)VE and Se deficiency of dairy cows during the perinatal period of the two cattle farms was more serious on the day of parturition and 10-20 days postpartum,and the disease incidence was higher.However,the oxidative stress and disease prevalence in farm A were lower than in farm B.(2)Compared with the healthy control group,dairy cows in the VE and Se deficiency group increased fat mobilization,occurrence of negative energy balance and ketosis,decreased plasma levels of GSH-Px and T-AOC,and increased MDA,but liver function,other mineral elements and vitamins were not affected.(3)There was a significant positive correlation between plasma levels of GSH-Px and Se and VE,a significant negative correlation between plasma levels of MDA and Se and VE,and a significant positive correlation between the levels of T-AOC and VE,it is established that GSH-Px and MDA can be used as the main early warning indicators of Se deficiency,and T-AOC can be used as the main early warning indicators of VE deficiency.Test 2.Effects of VE and Se supplementation on oxidative stress,immunosuppression,production performance and disease in dairy cows.The experiment was carried out on an intensive cattle farm in Heilongjiang Province.On the day of delivery,40 Holstein cows with similar parities and body conditions were selected as experimental animals,which were randomly divided into four groups,namely control group(C),VE supplemental group(VE),Se supplemental group(Se)and Se,VE + Se simultaneous supplemental group(VE + Se),with 10 cows in each group,and fed the same basic diet.The C group was not supplemented with Se and VE,the VE group was supplemented with 3000 IU VE at 7 and 14 days after calving repectively,the Se group was supplemented with 1.50 mg/kg BW/head in the basal diet,the VE + Se group was supplemented with 3000 IU VE and 1.50 mg/kg BW/head Se in the basic diet at 7 and 14 days after calving,respectively.The cows were followed up to postpartum 50 days,and blood samples were collected on parturition day and postpartum 7 days,14 days and 21 days.According to the significance analysis,Pearson correlation analysis and risk early warning assessment of the production data and blood biochemical indexes of experimental cows,the results showed that:(1)Plasma VE and Se levels in the three experimental groups were higher than those in the control group,and VE + Se group had the best supplemental effect.At the same time,the supplementation of VE and Se had no adverse effects on normal energy metabolism,liver function and kidney function,and the antioxidant capacity and immune function were improved,and the effect was more obvious in VE + Se group.(2)Supplementation of VE and Se can improve or maintain the normal reproductive performance of dairy cows,and reduce the occurrence of ketosis,mastitis,placenta retention,metritis,and postpartum infection,especially the effect of VE + Se is more obvious.When the blood level of VE or Se is maintained above a certain critical value,the risk of mastitis and metritis can be reduced more effectively.(3)The supplementation of VE and Se increased the economic return of dairy cows,and the net return of VE + Se group was the highest.In conclusion,there are serious VE deficiency and Se deficiency in perinatal cows in two intensive cattle farms in Heilongjiang Province.Supplementation of VE + Se can more effectively enhance the antioxidant capacity and immune function of dairy cows,improve the reproductive performance of dairy cows,reduce the incidence of disease and increase the economic benefits of dairy cows.GSH-Px,MDA or T-AOC were used as the early warning function of the risk of Se or VE deficiency,and the early warning threshold of the risk of mastitis and metritis caused by the levels of VE and Se were established,which provided the basis for the field monitoring of the effect of Se or VE deficiency and supplement in dairy cows in the future.