Postnatal attributes of spermatogenesis and Sertoli cell efficiency of Assam goat (Capra hircus) in a tropical environment

The present study was conducted in a total of eighteen numbers of healthy male Assam goats of
age ranging from birth to 10 months. The goats were divided into six age groups viz. group-I (0-
day), group-II (2 months), group-III (4 months), group-IV (6 months), group-V (8 months) and
group-VI (10 months) consisting of 3 animals in each group. The mean nuclear diameters of the
Sertoli cells registered an increase in their values with the advancement of the age of the male
goats. The efficiency of spermatogonial mitosis as determined by estimating the ratio between
pachytene primary spermatocytes and type A spermatogonia increased noticeably from 4 months
of age (group-III) being the maximum in 10 months old goats. The overall rate of
spermatogenesis as measured by recording the ratio between round spermatids and type A
spermatogonia increased significantly between 6 and 8 months of age. Further, the overall
Meiotic Index (ratio between round spermatids and pachytene primary spermatocytes) was
recorded to be 2.45 ± 0.56, revealing about 38.75 percent cell apoptosis (loss) in Assam goats.
The ratio between round spermatids and Sertoli cell nuclei increased in older goats and the
Sertoli cell efficiency was found to be the maximum in 10-month-old goats as almost 16. Twelve
spermatids were found for each Sertoli cell at this age.