26 Factors effecting collection characteristics in beef bulls at an artificial insemination facility

Abstract

Abstract Increased genomic information available for young bulls has decreased age at time of semen collection. Factors effecting collection characteristics include collection method (electro ejaculate (EE), or artificial vagina (AV), and the number of ejaculates collected. The objective of this study was to determine the effect of managerial factors on collection characteristics. From 2008 to 2018, 11,642 individual ejaculates were analyzed by a single technician at the Kansas Artificial Breeding Service Unit. Bulls that were not receptive to the AV after 3 or 4 attempts, were subject to EE. Collection characteristics were evaluated using multiple regression models; fixed effects included collection method, sequence of ejaculates collected per day, and were evaluated for their impact on collection characteristics. Progressive motility before freezing was greater (P< 0.0001) for bulls collected with EE compared to AV. Ejaculate volume for EE collections was greater (P< 0.0001) than those collected with AV. Percent spermatozoa with secondary abnormalities was greater (P< 0.05) for bulls collected with EE compared to AV. Concentration of spermatozoa per mL was less (P< 0.0001) for bulls collected with an EE (514 x106) compared to AV (617 x106). Total number of straws frozen per ejaculate were less (P< 0.001) for bulls collected with EE (94) compared to AV (108). The number of ejaculates collected per day was significant for the percent of spermatozoa with secondary abnormalities (P< 0.001). As ejaculate number per day increased, the concentration of spermatozoa decreased (713, 580, 535, and 434 x 106 per ml respectively; P< 0.0001) and the number of straws frozen per ejaculate decreased (123, 107, 93, and 82 respectively; P < 0.0001). In conclusion, AV collections resulted in a higher number of straws frozen. The method of collection could cause a significant impact when collecting young high demand bulls.