ATTAINMENT OF SPERMATOGENESIS IN SWEDISH CROSSBRED BOARS

Twenty peripubertal Swedish cross-bred boars were used to study the te sticular differentiation and the maturation of spermatozoa (epididymal ) between 100 and 180 days of age. In all animals the sex cords were s mall and solid at 100 days of age. Spermatogenesis started at approxim ately 115 days of age and was completed, i.e. the cellular organizatio n of the seminiferous tubules indicated a sexually mature testis with normal spermatogenesis, at 180 days of age. By 125 days of age only a few spermatozoa were found in the cauda epididymidis. Furthermore, a h igh frequency of sperm morphological alterations were seen. The sperm concentration in the cauda increased with increasing age, and simultan eously the frequency of abnormal spermatozoa decreased. However, not a ll boars had a 'mature' semen picture in the cauda epididymis at 180 d ays of age.