Reproductive performance of dairy cows with relation to time of ovarian cyst formation

The aim of the study was to explain whether or not the time of ovarian cyst (OC) formation had an influence on reproductive performance in dairy cows. Eighty cows with OC (group A - first OC diagnosis < 42 d postpartum; group B first OC diagnosis > 42 d postpartum) were compared with 80 control cows without OC matching in lactation number and calving date. Milk yield was higher in OC cows compared with control animals (P < 0.05). With respect to reproductive measures, group A did not differ from the control group. Reproductive performance of group B was lower than in the control and A groups. Treatment of OC did not have any effect on fertility measures. Additionally, ovarian cysts were diagnosed more often in cows with than without endometritis (P < 0.05). In conclusion, ovarian cysts diagnosed after the puerperium had a negative effect on fertility, whereas OC diagnosed during the puerperium did not affect reproduction.