Reproductive tract inflammatory disease in postpartum dairy cows.

Up to half of dairy cows are affected by at least one of metritis, purulent vaginal discharge, endometritis or cervicitis in the postpartum period. These conditions result from inadequate immune response to bacterial infection (failure to clear pathogenic bacteria from the uterus) or persistent inflammation that impairs rather than enhances reproductive function. The degree of mobilization of fat and how effectively it is used as a metabolic fuel is well recognized as a risk factor for metabolic and infectious disease. Release of non-esterified fatty acids has direct effects on liver and immune function but also produces pro-inflammatory cytokines (tumor necrosis factor α and interleukin-6), which contribute to systemic inflammation and to insulin resistance. Therefore, reproductive tract inflammatory disease may be a function of both local and systemic inflammatory stimuli and regulation as well as regulation of fat metabolism. Better understanding of variables associated with insulin resistance and inflammatory regulation in the liver and adipose tissue may lead to improvement of reproductive tract health. This paper reviews factors that may contribute to postpartum reproductive tract inflammatory diseases in dairy cows and their inter-relationships, impacts and treatment.