2019 Volume 72 Issue 9 Pages 539-544
The number and motility of sperm decreased dramatically and Oligospermia occurred at five years of age in a Holstein bull after four years waiting in a progeny testing program. Libido, erection ability and ejaculation were normal, but sperm concentration, total sperm output, sperm motility and sperm viability in ejaculates decreased dramatically, and the abnormal sperm morphology rate increased. The basal concentration of circulating testosterone was at a normal level, and the pattern of testosterone secretion from the testes in response to a single intravenous administration of human chorionic gonadotropin showed a normal reaction. The size and weight of the testes were remarkably small as compared with normal bulls. Thinning of the convoluted seminiferous tubule in the curved seminal vesicle, thickening of the curved refined duct wall, and undulation of the elastic fibers were observed. Increased collagen fibrils, small vessel proliferation, lymphocytes and plasma cell aggregation were observed in the testicular stroma. In the right epididymis testicular export tube, stenosis and obstruction due to fibrous granulation were confirmed to a limited extent. These results suggest that this case was suffering from a slow hematogenous exudative flame, mainly composed of testicular interstitium, causing testicular atrophy and oligospermia.
