Summary: | The purpose of the present research was to define ovarian follicular dynamics and plasma endocrine profiles in response to a single PGF<sub>2α</sub> injection, administered indiscriminately during the breeding season of Barbari goats. Ovarian dynamics were observed at every 12 h interval by using B mode ultrasonography, blood samples for hormonal analysis such as estradiol 17β and progesterone were collected at every 12 h interval, and bucks with aprons were used to identify standing estrus at every 6 h interval. Relative to PGF<sub>2α</sub>, the start of standing estrus and ovulation differ (<i>p</i> < 0.05) between early- (n = 7), intermediate- (n = 6), and late-responding (n = 6) goats. The highest plasma level of estradiol 17β was detected 12 h prior to ovulation. The average diameter of the ovulatory follicle and length of standing estrus were comparable (<i>p</i> > 0.05) between the goats. The corpus luteum degenerated more quickly (<i>p</i> < 0.05) in early- than intermediate- and late-responding goats. Dominant follicle diameter and estradiol 17β concentration also differ (<i>p</i> < 0.05) among groups. Although the plasma level of progesterone did not vary (<i>p</i> = 0.065), the variation in progesterone concentration with time differed (<i>p</i> < 0.05) amongst the goats. As a result, this research indirectly reveals that the beginning of standing estrus, end of estrus, and ovulation after PGF<sub>2α</sub> might fluctuate in Barbari goats because of follicular and hormonal dynamics during the luteal phase.
|