Association Of Inflammatory Cytokines In Perinatal Serum And Postpartum Lactation Performance

Perinatal dairy cows have frequent inflammation after calving.Dairy cows prone to get postpartum diseases such as nutritional metabolic diseases and metritis,endometritis.Nutritional metabolic diseases are easily to cause body’s subacute inflammation,metritis and endometritis can cause systemic acute inflammatory response.The current studies suggest that inflammatory responses can reduce the dairy cows’ lactation performance.Cytokines play important roles in the inflammatory response,including pro-inflammatory cytokines,anti-inflammatory cytokines,chemokines and so on.But the experiments about cytokines which are associated with lactation performance are less than others.Quantitative analysis about inflammatory cytokines in serum,including IL-4,IL-6,IL-1β,IFN-γ and TNF-α,are investigating the relationship between inflammatory cytokines and lactation performance.First,the dairy cows are sampled at 7 time points of the 1st and 2nd before prenatal and the 1st,3rd,7th and 10 th day after postnatal.Serum is collected by blood from the tail vein,and the inflammatory cytokines with significant changes in perinatal dairy cows are screened to find the point-in-time of significant change.At the same time,the concentration of cytokines at each time point is making the correlative analysis with milk production and composition in the early lactation.Then the information,blood,milk composition analysis of the 82multi-cow are collected,to calculate the correlation by statistical methods and to study the effect of different concentrations of inflammatory cytokines on lactation performance.The results show that:1)The level of IFN-γ and IL-1β are significantly increased from prenatal to the 1st day after calving,then return to normal from the 1st day to the 3rd day after delivery and not change significantly from the 3rd day to the 10 th day after delivery;IL-4 and IL-6 don’t have significant changes before and after calves;2)There is no significant effect of parity and postnatal physical conditions on IFN-γ on the first day of postnatal period(P>0.05);There is a significant negative correlation between IL-1β and parity(P<0.05)on the first day after calving,and the correlation is not significant(r =-0.29);There is a significant positive correlation between IL-1β and milk yield(P<0.05),and the correlation is not significant(r=0.28);3)The effect of IL-1β concentration on the first day postpartum on milk yield is significant.The higher concentration of IL-1β,the higher the total milk yield in 1 week postpartum(P<0.01),and the higher of milk yield in the early stages of lactation(P<0.05).The higher concentration of IL-1β,the higher yield of milk protein,lactose percentage and lactose;4)IL-1 beta >0.30 concentration,lactation performance is higher than that of IL-1 beta =0.30ng/m;When IFN-γ concentration is 2.00-2.99 ng / ml,the total milk yield is the highest in one week after postpartum(P<0.05);5)The concentration of IL-1β in postpartum has a longer effect on lactation perfotmance,and IFN-γ has no effects on lactation performance at the early stage of lactation.