Relationships among seminal culture, seminal white blood cells, and the percentage of primary sperm abnormalities in bulls evaluated prior to the breeding season

Semen samples from 100 beef breed bulls were evaluated for sperm morphology (phased contrast microscopy), seminal white blood cells, and the presence of potential reproductive pathogens. Eligibility required visualization of the glans penis throughout semen collection. Based on clinical spermiograms , bulls were grouped into normal, marginal, or unsatisfactory morphology cl assifications. The 3 experimental groups were similar in age and scrotal ci rcumference and differed significantly in the percentage of primary sperm a bnormalities. Most semen samples (94%) contained one or more potential repr oductive pathogens (Hemophilus somnus, Mycoplasma bovigenitalium. Arcanobac terium pyogenes and Ureaplasma diversum). No significant relationship could be demonstrated between primary abnormalities and the assigned culture sco re. Our experimental results suggest that clinicians should interpret clini cal semen culture results with great care. No significant relationship could be demonstrated between primary abnormali ties and assigned white blood cell (WBC) score, although, only 1% of the sa mples was scored >5 WBC per high power field. The use of seminal WBC score may be valid adjunct to routine semen evaluation when that threshold is the basis for clinical decisions. (C) 1999 by Elsevier Science Inc.