Comparison of efficacy of Ovsynch protocol to single PGF2α administration in treatment of individual dairy cows with post-service subestrus.

Abstract

The aim of this study was to evaluate the efficacy of the Ovsynch protocol in the treatment of post-service subestrus in individual dairy cows compared to a single administration of PGF2α. The study was performed on 517 Polish Friesian Holstein cows with post-service anestrus over four years in 3 dairy herds under a herd health program. Cows (n=240) diagnosed ultrasonographically as non-pregnant and with a mature corpus were treated with a single PGF2α administration and inseminated at detected estrus. Cows without corpus (n=277) were treated with the Ovsynch protocol. The estrus detection rate after PGF2α administration, percentages of cows pregnant after the treatment and at day 260, intervals from parturition to treatment and from treatment to conception and pregnancy loss rates were calculated. The overall percentage of cows pregnant after treatment did not differ between animals treated with the Ovsynch protocol and with PGF2α (38.9% vs. 42.5%; p>0.05). In herd A the percentage of cows pregnant after treatment was significantly lower (p⟨0.05) for the Ovsynch group than for the PGF2α group (30.2% vs. 61.2%). In contrast, in herd C the percentage of cows pregnant after treatment was significantly higher (p⟨0.05) in the Ovsych group than in the PGF2α group (39.6% vs. 28.8%). The overall estrus detection rate after administration of PGF2α was 59.6%. However, it was significantly lower (p⟨0.05) in herd C (44.7%) than in herds A (79.6%) and B (76.3%). The overall pregnancy loss rate ranged from 5.1% to 13.3% and did not differ significantly between herds and treatment groups (p>0.05). In conclusion, Ovsynch protocol can be a useful alternative for treatment of post-service suboestrus in individual cows in dairy herds with insufficient oestrus detection.