Evaluation of the Ovsynch and Co-synch protocols on estrus intensity and pregnancy rate in Anatolian buffalo heifers

Abstract This study aimed to evaluate the Ovsynch and Co-synch synchronization protocols in terms of estrus intensity and pregnancy rate in Anatolian buffalo heifers. To this end, 27 Anatolian buffalo heifers were used. For the Ovsynch synchronization protocol, GnRH (buserelin acetate, 12 μg) was administered on day 0, PGF2α (cloprostenol, 500 μg) on day 7, and GnRH (buserelin acetate, 12 μg) on day 9, and artificial insemination was performed 16-20 hours after the second GnRH application. For the Co-synch protocol, GnRH (buserelin acetate, 12 μg) was administered on day 0, PGF2α (cloprostenol, 500 μg) on day 7, and GnRH (buserelin acetate, 12 μg) along with artificial insemination on day 10. At the time of artificial insemination, estrus intensity was classified as intense, moderate, weak, or negative. Pregnancies were within 40 to 70 days after artificial insemination using pregnancy-related glycoprotein or ultrasonography examinations. Intense, moderate, weak, and negative estrus intensities were determined at rates of 20%, 20%, 26.6%, and 33.3%, respectively, in the Ovsynch group and 41.6%, 58.3%, 0%, and 0%, respectively, in the Co-synch group (P<0.05). Pregnancy rates were 30% and 75% in the Ovsynch and Cosynch groups, respectively (P<0.05). In conclusion, the Co-synch protocol was found to be more successful than the Ovsynch protocol for synchronization in Anatolian buffalo heifers. In addition, to increase the success of artificial insemination, it is recommended to perform cervix uteri monitoring and perform artificial insemination only on animals showing estrous behavior.