Özet:

Purpose: Repeat breeder is to the hormonal support applied after seed in cows; the study of the number of lactations, milk productivity and the effect of the day-to-day period in the mouth. In the study, 169 Holstein breeds were used, having at least one birth, having regular sexual cycles and having at least three seeds without pregnancy. PGF2+ovsynch estrus synchronization was applied to the cows involved in the study. The fixed-time seed cows (0. day) were divided into 4 groups. In the vagina of cows included in the first group (Group I, Progesterone group, n=42) in the 84th hour after the seed was placed the intravenous drug (PRID) of progesterone salan and was removed from the vagina on the 9th day. The cows included in the second group (Group II, hCG group, n=40) were applied hCG within the muscle on the 7th day. In the third group (Group III, Progesterone+hCG group, n=45), progesterone and hCG applications were combined. The animals in the fourth group (Group IV, Control group, n=42) were not treated. Results: The rate of conception on the 30th day after insemination was 40.47% in Group I; 37.50% in Group II; It was determined as 44.44% in Group III and 30.95% in Group IV (p>0.05). No statistically significant difference was found in the pregnancy rates in groups other than Group I according to the number of lactations (p>0.05). However, when all repeat breeder cows were evaluated, the conception rate of animals with ?3 lactation number was found to be lower than those with 1 and 2 lactation numbers. In addition, it was determined that as the milk yield increased in the cows in the control group, the rate of conception decreased (p<0.05). There was no statistical difference between the groups according to the days of the day (p>0,05). Recommendations: Repeat breeder cows have not statistically increased the rate of pregnancy in hormone applications performed after seminality; hormonal supported groups have found the rate of pregnancy higher than the control group.

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