Follicular dynamics in upgraded Philippine indigenous goats (Capra hircus)

Study I involved histological characteristics of goats ovary. Results revealed that most of the primordial follicles were found in the ovarian contex. The diameter of oocyte increased as the follicle developed. Secondary follicle had maximum oocyte diameter of 60 micrometers whereas tertiary and Graafian or preovulatory follicles had maximum oocyte diameter of 110 and 140 micrometers, respectively. The corpus luteum is formed from ovulated follicles which contained large luteal cells (LLC) and small luteal cells (SLC). The maximum size of LLC was 30 micrometers (n=10) and SLC had 20 micrometer (n=10). The corpus albicans were seen located at the periphery of the ovarian cortex. Study 2 dealt with ovarian morphometry and follicular population. The highest ovarian weight, length and width was found among old goats with 1.90 g, 22.2 mm, and 16.3 mm, respectively (P0.01). This was attributed to the presence of corpus luteum and large follicular surface of ovulated follicles. Prepubertal goats had the highest number of primordial follicles with a mean of 15,375.1 followed in descending order by old and pubertal goats with 12,266.6 and 9,266.7, respectively (P0.01). The primordial follicles did not decrease as the age of the animals increased. However, with regards to the number of growing, secondary and tertiary follicles, the trend decreased as the age of the animals increased. The number of corpus luteum was found highest among old goats with a total of 16 out of the 10 ovaries used (P0.01). This was followed by pubertal and prepubertal with 10 and 3 corpus luteum, respectively. The various age groups had high number of early antral follicles with 57, 44 and 40 follicles for pubertal, prepubertal and old goats, respectively. Small antral follicles were fewer compared to early antral follicles with 22, 20 and 9 follicles for old, prepubertal and pubertal goats, respectively. The percent follicular phase was found highest among prepubertal with 96.25% whereas the percent luteal phase was highest among old goats with 17.78%. Study 3, focused on the quantity and classification of follicular non-atresia and atresia. Results showed that the quantity of non-atresia was found highest among pubertal goats with 23.60% whereas the highest percent atresia was found among old goats with 91.90%. The classification of atresia was found highest in strongly atretic with 62% observed among old goats. This was followed by intermediately atretic with 36.7% observed among pubertal goats. There was no incidence of cystic atresia found in any age groups in goats.