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 ef iciency 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 signi icantly 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 ef iciency 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.