Effect of purulent vaginal discharge on ovarian cyclicity, pregnancy, pregnancy loss, and cow survival in a large multi-farm population of Holstein cows
Uterine diseases, such as metritis and endometritis, are highly prevalent in dairy cows. Clinical endometritis, more precisely identified as purulent vaginal discharge (PVD), is characterized by presence of purulent (>50% pus) uterine discharge detectable in the vagina ≥21 days after parturition, or mucopurulent (approximately 50% pus, 50% mucus) discharge detectable in the vagina >26 days postpartum. This condition has been associated with variable degrees of reduced fertility; however, the reported effects on subsequent survival in the herd are conflicting. The analysis of a large experimental data set, using a standardized disease definition would help to clarify these long-term responses. Therefore, the objective was to analyze the effect of PVD on multiple reproductive responses and survival in a large population of Holstein cows across US regions.