Morpho- and Histometric Evaluations on the Testis and Epididymis in Buffalo Bulls During the Different Reproductive Seasons

Some morphometric parameters of the buffalo gonad and epididymis were compared in the mating (late autumn-winter) versus non-mating (late spring to the beginning of autumn) seasons. Organs from mature bulls of proven fertility were collected at slaughtering in February and September and used for this study. Testicular and epididymal diameters and weights were measured. The diameters of the testicular seminiferous tubules, as well as the diameters of the ductal lumen in sections taken from caput, corpus and cauda, were compared on haematoxylin and eosin-stained sections. The height of epididymal principal cells was also measured, from the basement to the apical membrane. The data obtained in the two seasons were analyzed by ANOVA, co-variating the histometric data for testicular and epididymal weight, respectively. Season-related differences were observed. Testicular and epididymal weights were higher during the mating period, as well as the organ lengths. Spermatogenesis was conserved in the resting period, but the testis showed smaller tubular diameters. In the epididymal caput and corpus the tubular diameters and epithelial cell height were significantly diminished in summer. On the contrary, tubular diameter and epithelial cell height of cauda epididymis increased during the summer, due to accumulation of non-ejaculated spermatozoa. Seasonal variations of genitalia recorded in buffalo bulls could represent an interesting aspect affecting fertility, which might influence the quality of semen and, in turn, the chance of cryopreservation. Morphometric studies of reproductive organs could contribute to better develop the reproductive potential in this species.