Influence of health status of reproductive organs on uterine involution in dairy cows

The effect of parity and pathology of the uterus and ovaries on uterine involution was investigated in 57 primiparous and 258 pluriparous dairy cows under dairy farm conditions. Involution of the uterus was determined by gynaecological examination including ultrasonography at 2-3 d intervals from the end of the first week postpartum till its completion. A significant effect of parity at normal and pathological puerperium and of puerperal complications (retained placenta and/or puerperal endometritis, ovarian cysts) on the course of uterine involution was observed. Animals with normal puerperium showed complete involution in 23.0 +/- 5.3 d on average in primiparous and in 27.3 +/- 5.5 d in pluriparous cows. The pathological puerperium involving retained placenta and/or puerperal endometritis and ovarian cysts prolonged uterine involution in both primiparous and pluriparous cows by approx. 10 d. By day 40 postpartum the uterine involution was completed in all the primiparous and in 97.1% pluriparous cows with normal puerperium. By this time only 86.2% of primiparous and 70.6% of pluriparous cows with puerperal complications showed complete uterine involution. Serious postpartum endometritis with cervical discharge lasting longer than 3 weeks significantly prolonged uterine involution beyond day 40. We may conclude that the uterine involution in dairy cows, kept under farm conditions, is lengthened significantly by the parity, retained placenta, and/or puerperal endometritis and ovarian cysts.