Ovarian Dynamics and Changes in Estradiol-17β and Progesterone Relationship with Standing Estrus, Preovulatory Follicles, and Ovulation Using Single Prostaglandin F2α Injection in Barbari Goats

SIMPLE SUMMARY: There is an enormous goat population in Asia, especially in China, India, and Pakistan. Different estrus synchronization protocols such as Ovsynch and PGF(2α) are widely used in reproductive biotechnology to optimize estrus and ovulation in small ruminants to improve reproductive efficiency. Efficient small ruminant production depends upon the knowledge of re productive physiology. This study provides knowledge about the correlation among physical and behavioral signs of estrus with ovarian dynamics and hormonal profiles such as estradiol-17β and progesterone after induced luteolysis during the preovulatory period in Barbari goats. The findings of this study will be helpful in developing better estrus synchronization strategies for improving the reproductive efficiency of Barbari goats. ABSTRACT: The purpose of the present research was to define ovarian follicular dynamics and plasma endocrine profiles in response to a single PGF(2α) 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(2α), the start of standing estrus and ovulation differ (p < 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 (p > 0.05) between the goats. The corpus luteum degenerated more quickly (p < 0.05) in early- than intermediate- and late-responding goats. Dominant follicle diameter and estradiol 17β concentration also differ (p < 0.05) among groups. Although the plasma level of progesterone did not vary (p = 0.065), the variation in progesterone concentration with time differed (p < 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(2α) might fluctuate in Barbari goats because of follicular and hormonal dynamics during the luteal phase.