Ligation and sclerosis of the epididymis in the bull

In an attempt to induce permanent aspermia the caudae epididymes of 17 bulls were subjected to ligation or injection with ethanolamine or chlorhexidine in dimethyl sulphoxide. Nylon and polyglycolic acid ligatures had little or no effect on the sperm counts although these materials were used in only three bulls. Steel ligation induced aspermia of several weeks' duration in four of six bulls. Although the effect in at least three of these animals might have been permanent, the trial was discontinued because the other two bulls, treated identically, showed little response. Ethanolamine injected into the epididymis also had little or no effect on the ejaculate. By contrast the chlorhexidine preparation produced an almost immediate aspermia sustained until the bulls were slaughtered a year later.