Uterine health in the postparturient period of the dairy cow

Abstract: The main objective for dairy farmers is to produce the best amount of milk from healthy cows. When doing so the optimization of reproductive efficiency is a key variable. Uterine diseases in the postpartum period are among the main reasons for this goal not to be achieved. It is estimated that up to 90% of all dairy cows have bacterial contamination of the uterus during the first two weeks after calving, something that usually is taken care of by the process of uterine involution. However, the involution is not always fully effective and a large part of the cows show signs, clinically or microscopically, of ongoing bacterial infection even after the involution is completed. The diversity and differences in composition between the microbiota of the healthy and diseased uterus in cows are not yet fully understood. Altough several potential causative pathogens have been identified, the complete comprehension of the pathogenesis of metritis and endometritis is still unknown. The immune defence in the postpartum uterus is mainly depending on mucosal defence systems and innate immunity. It is shown that cows suffering from negative energy balance has an impaired total white cell count as well as a reduced efficiency of the innate immune response. This may prolong the bacterial contamination and is in many cases the cause of a subclinical chronic inflammation of the endometrium that remains undiagnosed. Today there is no diagnostic method that is considered to be gold standard to evaluate subclinical inflammation of the endometrium. This study aims to investigate the certainty in one of the diagnostic methods available and also investigate the correlation between negative energy balance and persistence of inflammation in post-partum dairy cows.