Abstract:

Purpose: The presented study aimed at determining the effects of target breeding and presynchovsynch synchronization protocols on the rate of pregnancy in the first seed. Method and method: The study used a healthy Holstein breed of cow between 30-35 days of postpartum and 2,5-6 years old. The cows were first performed rectal and ultrasound examinations, and animals that had no problems in the genital system were included in the study. The animals were divided into three groups. The first group (Target breeding, n=60) cows are PGF2 3 times between 14 days. The injection was made. The third PGF2? The animals that showed estrus until 72 hours after the injection were seed. Animals that don’t show estrus were seed in a fixed time at 80 hours. The second group (Presynch-Ovsynch, n=50) is PGF2 twice between 14 days. The injection was done and the second PGF2? 12 days after the injection, the Ovsynch protocol began. The third group (Control, n=50) has not been applied to cows. The postpartum first day of fertilization and pregnancy rates were recorded. The pregnancy examination of cows after seed was carried out with ultrasound in the 30th day. Results: In target breeding, presynch-ovsynch and control group, pregnancy rates were set as 36.66% (22/60), 32.0% (16/50) and 24.0% (12/60) respectively (p>0.05). The latest PGF2 in the target breeding group? In 72 hours after the injection, 38 (63.33%; 38/60) injections were observed. The pregnancy rates of cows that were detected and seated and that were seated for a fixed time without a estrus were 42.10% (16/38) and 27.27% (6/22) respectively. Recommendation: In the target breeding and presynch-ovsynch groups, the rate of pregnancy after the first seed has not increased statistically, but in these groups, the rate of pregnancy has been higher than in the control group. As a result, it is believed that these synchronization protocols may have a positive effect in the first service period, but with more animals, new studies should be carried out.

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