Immune Function and Energy Status in Holstein Cows with Uterine Infections

The postpartum uterus in dairy cows is susceptible to multiple bacterial pathogens and susceptibility to infection appears to be associated with periparturient immunosuppression and energy status. Neutrophils (PMN) play an important role as they provide the first-line of cellular defense against bacterial colonization within the uterus. Peripheral blood PMN functions of periparturient dairy cows are impaired relative to non-parturient cattle (Kehrli et al., 1989; Cai et al., 1994). Blood PMN functions begin to decline prior to parturition, reach a nadir shortly after parturition, and slowly return to prepartum levels by about 4 wk postpartum (Kehrli et al., 1989). Although impairment of PMN function in periparturient dairy cows has been established, factors associated with PMN impairment around the time of calving are largely unknown.