[Trials of artificial vaginas for bulls (author's transl)]

Introduction of short artificial vaginas with smooth plastic inner liners and without any internal pressure reduced the bacterial contamination of bull semen to a very considerable extent. Moreover, semen production increased, partly because of lower semen losses in short artificial vaginas with smooth inner liners which were not under pressure, partly because more intensive sexual preparation of the bulls was required to collect semen with this type of artificial vagina. When adequate sexual preparation of the bulls is practised, all bulls will accept short artificial vaginas with smooth inner liners which are not under pressure. The use of particularly rough rubber inner liners in artificial vaginas for bulls and using long artificial vaginas with internal pressure is not advisable because of unnecessarily high semen losses in the artificial vagina and unnecessary contamination of the crude semen.