Daily sperm production of zebus (Bosindicus) estimated by quantitative histology of the testis

Abstract Microscopic parameters were studied quantitatively in testes from six Nelore zebus (Bosindicus), aged 4 to 6 years, with normal spermatogenesis, which were kept at sexual rest. Ratios of germ cell nuclei, counted in cross sections of seminiferous tubules, indicated that cellular losses in the spermatogenic process of the zebu are higher than those observed in taurines. Daily sperm production, estimated from the number of round spermatids in stage 1 of the cycle of the seminiferous epithelium and the duration of this cycle, was (mean ± SD) 12.2 ± 0.9 × 10 6 spermatids/gram of testis parenchyma/day and 2.6 ± 0.5 × 10 9 spermatids/testis/day. These values are smaller than those of taurines.