Investigation And Risk Assessment Of Oxidative Stress And Immunosuppression In Dairy Cows During Perinatal Period In Two Intensive Dairy Farms In Heilongjiang Province

Oxidative stress and immunosuppression are important issues affecting the health of perinatal dairy cows,and Can lead to declines in animal welfare and economic losses.Due to the lack of domestic assessment of oxidative stress and immunosuppression in perinatal dairy cows,this study selected two intensive cattle farms in Heilongjiang Province to perform blood pathology analysis of energy metabolism,minerals,trace elements,and oxidation in perinatal cows.Through cross-sectional research method,combined with significance analysis,correlation analysis,regression analysis and ROC analysis,aim is to understand the nutritional metabolism and health of perinatal dairy cows and their relationship with oxidative stress and immunosuppression,and to perform risk assessment of oxidative stress and immunosuppression in perinatal dairy cows.It will lay a foundation for effectively monitoring and prevention of oxidative stress and immunosuppression in dairy farms in the future.This study randomly selected 20 dairy cows from 7 to 21 days before delivery in two intensive cattle farms(A and B)in Heilongjiang Province,delivered 20 cows on the same day and 20 cows from 7 to 21 days postpartum,and developed blood biochemical indicators as well as pasture feed formulation analysis.The results showed that there were significant differences in oxidative stress and immune suppression among prenatal,parturition and postpartum dairy cows during the perinatal period.The risk factors for oxidative stress and immune suppression on the day of delivery and postpartum were higher than those before delivery.Moreover,the risk factor for oxidative stress and immune suppression in the B-field was higher than that in the A-field.The research investigated the incidence of negative energy balance of 120 postpartum dairy cows in two intensive cattle farms(A and B)in Heilongjiang Province and found that the incidence of the two cattle farms were 26.67% and 50%,respectively.Then,the blood clinic pathological studies of cows with energy negative balance were carried out.The results indicated that the levels of GSH-Px,CAT,Se,T-NOS and VE in the blood of cows with negative energy balance were reduced,and the levels of MDA and Cu in blood were increased,with oxidative stress existing in the body.Spearman correlation analysis and binary logistic regression model were applied to determine the early warning effects of GSH-Px,CAT,MDA,VE,Se and BHBA on postpartum oxidative stress in dairy cows,and combined with ROC analysis to definepre-warning value of GSH-Px and CAT in plasma.The pre-warning values were following:GSH-Px<619.28U/L,Sensitivity78.3%,specificity66.7%;CAT<7.87U/mL,Sensitivity73.9%,speci ficity91.7%;Se<0.51Mg/L,Sensitivity79.2%,specificity 58.9%;BHBA> 0.72 mmol/L,Sensitivity100%,specificity 83.3%.Therefore,negative energy balance,VE deficiency and Se deficiency were risk factors for postpartum oxidative stress in dairy cows,but VE had not become an early warning indicator.The negative energy balance and mineral metabolism disorders of 120 postpartum dairy cows in two intensive cattle farms(A and B)in Heilongjiang Province were investigated.The clinical pathological analysis of the blood showed that:with disorders of mineral metabolism,Ca and Mg in blood significantly reduced,and IL-1,IL-2,IL-6,HP,CRP and TNF-? in blood were significantly increased,with immune suppression presented in the body.Then,Spearman correlation analysis and binary logistic regression model were applied to determine the early warning effect of Ca,Mg,IL-1,IL-2,IL-6,HP,TNF-? and BHBA on postpartum immune suppression in dairy cows,combined with ROC.The pre-warning values of plasma IL-1,IL-2,IL-6,HP,TNF-? and BHBA were defined as follows:IL-1>162.8ng/L,Sensitivity 77%,specificity78.4%;IL-2>329.8ng/L,Sensitivity68.8%,specificity79.2%;IL-6>15.9ng/L,Sensitivity75%,specificity83.3%;HP<29.49ng/L,Sensitivity81.3%,specificity52.5%;TNF-?<219.9ng/L,Sensitivity75%,specificity62.5%;BHBA>0.72mmoI/L,Sensitivity100%,specificity83.3%.Therefore,negative balance of energy and low Ca were risk factors for postpartum immune suppression in dairy cows,but Ca had not become an early warning indicator.Conclusion: This study found that the problem of negative postnatal energy balance,mineral metabolism disorder,lack of Selenium and vitamin E in dairy cows in two intensive Cattle farms in Heilongjiang Province is relatively Serious.It was very clear that postpartum energy balance,low Ca and lack of Se and VE in dairy cows were risk factors for oxidative stress and immune suppression.Blood GSH-Px,CAT,Se,and BHBA were established as early warning indicators of oxidative stress and its early warning values,and blood IL-1,IL-2,IL-6,HP,TNF-?,BHBA,as early warning indicators of immune suppression and its early warning values.