Oviductal cells adhesion test for bull semen quality assessment and fertility prediction of endangered breeds: Proposal of a simplified method

Classical procedures for semen evaluation in breeding soundness examination require time and are costly. The evaluation techniques with CASA are limited due to the lack of standardization among laboratories and data analysis methods. Recent studies have contradictory conclusions on the actual predictive ability of this method alone regarding fertility. Finding a simple and objective test that can give the maximum correlation between in vitro and in vivo results has been the main focus of novel research. In this study, we aimed to develop a repeatable protocol of sperm adhesion test using oviductal explant (AOC) and the results were compared with computer-assisted semen analysis (CASA) parameters along with field fertility. After the developmental phase, AOC was applied to a group of endangered Burlina breed bulls in which effective field results are difficult to obtain due to the narrow range of the population. The AOC test was found to be proficient enough to provide a prediction on bull semen fertility. Counting the sperms adhered in three microscopic fields after a coincubation period of 20 min in phosphate buffered saline (PBS) can provide useful information on the field level of fertility. The AOC test gives additional information to complement the standard semen evaluation methods that can be applied to endangered breeds as well.