Breeding soundness examination of 1, 952 yearling beef bulls in North Carolina

Abstract

During a 12-yr period, breeding soundness examinations (BSE) were performed on 1, 952 yearling bulls of 4 different breeds: Angus (n = 852); Charolais (n = 205); Polled Hereford (n = 520); and Simmental (n = 375). The yearling bulls had satisfactorily completed a record of performance test at 1 of 4 North Carolina test stations. The 1976 BSE guidelines of the Society for Theriogenology were used; however, semen analysis was not always conducted as determined by test station policy, and thus fewer bulls had a satisfactory score while more bulls had a questionable score when semen analysis was also performed. No statistical difference was observed in bulls scoring unsatisfactory between years with and without semen analysis. Overall, 85.2% were classified as satisfactory, 9.0% as questionable and 5.7% as unsatisfactory. The mean BSE score was 77.0. Simmental bulls had the largest mean scrotal circumference (SC), followed by Angus, Charolais and Polled Hereford bulls. Final test weight had the greatest effect on SC. Mean sperm motility score was 12.8, and mean total sperm abnormalities 24.9%. Penile fibropapillomas were diagnosed in 2.8% of the yearling bulls. The incidence rate of persistent frenulums was 4.4%. Angus bulls had the highest incidence of penile fibropapillomas and persistent frenulums. The incidence of persistent frenulums was greater (P < 0.01) in 11-mo-old bulls than in 12- to 15-mo-old bulls. Breeding soundness examinations of 11- to 15-mo-old bulls provide valuable information for selecting bulls for breeding programs.