Valoración de la respuesta ovárica a la adición de eCG en un protocolo de sincronización a tiempo fijo en vacas Holstein

Abstract

The objective of this research was to evaluate the ovarian response. It was measured in number of follicles, the preovulatory follicle size and the percentage of ovulation, including 400IU of equine chorionic gonadotropin (eCG) hormone, in the fifth day of a synchronization protocol with progestogens. It was found in native Holstein cows, in their postpartum period. In this work thirty cows were used. They were between two and five partum with body condition of 2,75 to 3,5 which were assigned to two treatments. It was divided in groups of fifteen animals each: T1 or control (n=15) and T2 or experimental (n=15) with addition of eCG. The ultrasonographic diagnosis was to make in the day 0 or when the treatment was to start with progestogens. On the day 5 and 8, so it can be determined follicles number in each moment. The days 10 and 11 were to obtain the preovulatory follicle size as well as the presence of ovulation in both treatments that were to study. The data was processed and analyzed with the program SPSS® version 22, where it was determined that: in the variable number of follicles recruited, in its treatment 1 and 2 for the day 0, an average of 5,7±0,69 and 5,4±0,83 was obtained. For the day 5, it was with an average of 7,6±0,79 and 9,0±0,95, and for the day 8 it was 7,3±0,86 and 10,1±1,07 respectively; in where they did not determine statistical significance (p>0,05). In the variable size of preovulatory follicle, an average of 15,8±0,88 were obtained in the treatment 1 and 14,9±0,97 in treatment 2, but these were not significant numbers (p>0,05). The analysis of ovulation in its percentage in the T1 got 86,7 %, and in the T2 got 73,3 % of ovulation. It was not determined statistical significance (p>0,05). Finally, the results were to get with the eCG addition in the 5 day in the treatment of progestogens, it did not have effect in the ovarian activity.