A survey of Southeast U.S. beef veterinarians regarding methods for bull breeding soundness evaluation

Abstract

The purpose of this survey was to describe veterinarians’ methods for performing bull breeding soundness evaluations (BSEs). Veterinarians in Mississippi, Louisiana and Arkansas were emailed a survey regarding their experience, demo­graphics, opinions and perceptions of client pref­erences regarding BSEs. Logistic regression was used to test respondent characteristics for associations with dichotomous outcomes including evaluating semen morphology as part of every BSE and detecting the diadem defect. Of 3,757 veterinar­ians solicited, 204 (5%) responded and 83 (2%) qualified for analysis. Of these, 10/73 (14%) indicated they do not evaluate morphology during every BSE. When shown an image of the diadem defect, 18/73 (25%) indicated seeing it often or some­times, and 55/73 (75%) indicated rarely or never. The only fac­tor associated with evaluating morphology as part of every BSE, was indicating belief that morphology was most predic­tive of bull fertility vs. believing motility was most predictive, or being unsure (OR = 11.2, 95% C.I. = 1.3-94.1). Respondents who always evaluate morphology with bright field microscopy at 1,000X (OR = 4.1, 95% C.I. = 1.2-13.3) or with phase contrast microscopy at ≥ 400X (OR = 5.4, 95% C.I. = 1.1-27.7) had higher odds of indicat­ing they detect the diadem defect sometimes/often. There was an interaction between always using 1000X magnification, or not, and always using 400X, or not, on the reported detection of the diadem defect. Veterinarians’ perceptions of which as­pects of the BSE are most predictive of fertility influence their methods for performing BSEs, and influence the frequency of detecting diadem defects.