The influence of experimentally induced copper deficiency on the fertility of rams. II. Macro- and microscopic changes in the testes.

The macro- and microscopic changes of the testes caused by molybdenum as well as a molybdenum plus sulphate induced copper deficiency were investigated in S.A. Mutton Merino rams. Judged on testes measurements, the testes development of rams suffering from a severe copper deficiency was slower (P less than or equal to 0.05) when compared with rams in the control group. Histological examinations of the testes of the rams which suffered from a severe copper deficiency revealed that the seminiferous tubules were less developed and less active than those of the control group. This was mainly due to the inactivity of the Sertoli cells. Where rams suffered from a copper deficiency, the Sertoli cells contained only a small volume of cytoplasm. The typical fingerlike cytoplasmic evaginations of the Sertoli cells into the lumen of the seminiferous tubules were absent while the nuclei of these cells were darkly stained, in some cases even pycnotic. Spermatocytogenesis was normal because primary spermatocytes with dark stained thread-like chromatin were observed in most of the seminiferous tubules. The process of spermiogenesis (metamorphic phase) did not take place. This can be accounted for by the inactivity of the Sertoli cells.