Comparative Evaluation of Ovsynch and Double Ovsynch Protocols with Single and Double Insemination in Holstein Dairy...

This study investigated the reproductive and economic costs of four estrus synchronization protocols in multiparous Holstein dairy cows: Ovsynch with one or two artificial inseminations (AIs), and Double Ovsynch with one or two AIs. A total of 216 clinically healthy cows were randomly assigned to one of the four treatment groups (n = 54 each). Pregnancy diagnosis was performed by transrectal ultrasonography at 33 days post insemination. Economic calculations included the cost of hormonal treatments, insemination, and pregnancy diagnosis, reflecting market prices in large scale Romanian dairy operations. The highest pregnancy rate (64.8%) and lowest cost per confirmed pregnancy (EUR 89.51) were achieved in the group treated with Double Ovsynch followed by a single AI. The standard Ovsynch protocol with one AI yielded the lowest conception rate (42.6%), indicating limited effectiveness under fixed-time AI conditions. These findings suggest that Double Ovsynch with a single insemination is the most effective and economically viable protocol for reproductive management in intensively managed dairy herds.