Treatment of Ovarian Cysts in Dairy Cows with Simultaneous Administration of GnRH and PGF2α has no Clear Advantage Over the Use of GnRH Alone

The aim of the study was to determine the therapeutic efficacy o f simultaneous administration of GnRH and PGF2α in dairy cows with ovarian cysts. Ovarian cyst-affected dairy cows were divided into two experimental groups: 54 cows treated with GnRH and PGF2α, and 42 cows treated with GnRH alone, whereas 22 untreated cows served as the control group. Clinical response and reproductive performance were evaluated. The cumulative disappearance was better in treated cows than in the control group; however, there were no differences between the treatment groups (92.6; 95.2% vs. 72.3%). The mean interval from calving to conception was not significantly shorter (being so by 29 d) in the GnRH/PGF2α group than in the cows treated with GnRH alone (P > 0.05). The intervals from treatment to conception were also similar in these groups. The pregnancy rate in both treated groups was similar (62%) and higher than in the control cows (53%). In the cows with luteal cysts, the total pregnancy rate was higher in all experimental groups; however, only in GnRH-treated cows was this difference statistically significant (77.8% vs. 50.0%, P < 0.05). With time after parturition, the pregnancy rate decreased in all groups. In general, the cows treated with GnRH and PGF2α simultaneously displayed a good clinical response and slight improvement in reproductive performance compared to the single-therapy GnRH group; however, this was not fully convincing.