Changes in the structure and function of the testes and epididymides in vasectomized rams.

Vasectomized rams were studied with regard to the structure and function of their testes and epididymides at different periods up to 3 years and 9 months after the operation, and compared with intact control rams. Control rams showed a marked seasonal pattern with higher values for size and weight of testes, diameter of seminiferous tubules, Sertoli cell ratios for germ cells, and size of cauda epididymidis immediately prior to and during the breeding season than at other times of the year. In vasectomized animals the seasonal pattern was ill-defined, the testicular parameters were lower, and the cauda epididymidis was larger than in intact rams. Spermatogenesis was qualitatively and quantitatively affected after vasectomy, with a sequential ebb-and-flow pattern of spermatogenic arrest and hypospermatogenesis. Epididymal changes included the development of multiple spermatoceles surrounded by a granulomatous reaction, and disturbances in the process of sperm maturation.