Changes in the Epididymis Associated with Morphological Changes in the Spermatozoa

Supplementary estrogen given to four bulls produced large numbers of spermatozoa with looped or bent tails. Spermatozoa from the testis, head, and body of the epididymis failed to show these abnormalities, whereas those collected from the tail were abnormal. Changes found in the spermatozoa were accompanied by degeneration in the epididymal epithelium, and supplementary testosterone failed to counteract the changes produced by the estrogen. In four bulls producing large numbers of abnormal spermatozoa spontaneously, no other evidence of faulty endocrine function was present, indicating that the impaired function of the epididymis caused changes in the spermatozoa. The observations also indicate that estrogen acted directly on the epididymal epithelium.