Ovarian follicular dynamics during the interovulatory interval in Najdi goats

Abstract

The pattern of growth and regression of ovarian follicles was characterized during the estrus cycle in 5 Najdi goats by daily ultrasonographic examination of the ovaries. Follicles 2 mm was measured and their relative locations within the ovary were determined to follow the sequential development of each individual follicle. Results indicated the presence of either four (n = 2 estrus cycles) or five (n = 3 estrus cycles) waves of follicular growth during the interovulatory interval. Each wave was characterized by the development of at least 1 large follicle (dominant) and a variable number of small follicles (subordinate). The mean number of follicular waves in Najdi goats is 4.6 ± 0.55, the days of wave emergence were on -0.8 ± 1.06, 3.2 ± 0.4, 7.0 ± 0.6, 12.3 ± 1.72 and 13.0 ± 1.63, for the first to fifth follicular waves, retrospectively. In goats with four or five follicular waves the dominant follicle in forth or fifth wave was ovulatory follicle. The mean number of ovulations in Najdi goats is 1.8 ± 0.4. Means of values were analyzed by repeated measures test using general linear model (GLM).

Key words: Goats, estrous, follicles, ultrasonography.