Sperm quality in naturally infected rams with Brucella ovis

- Natural infection with B. ovis not affect scrotal circumference and volume ejaculate.
- Natural infection with B. ovis negatively affect sperm quality.
- The negative effects on sperm quality was regardless of the presence of epididymal lesions.
- Serological analysis to B. ovis should be a component of the evaluation of fertility.

Ovine epididymitis caused by Brucella ovis is a chronic disease, characterized by testicular and epididymal alterations, which cause loss of fertility in rams. However, infected rams without clinical signs, may have decreased fertility and be excreting the bacteria. The aim of this study was to evaluate sperm quality in serologically positive to B. ovis naturally infected rams. Seminal samples were obtained of 207 rams to evaluate seminal volume, sperm concentration, mass motility, vitality, presence of somatic cells and percentage of abnormalities. Clinical examination was performed by palpation. The serological response against B. ovis was evaluated by double immunodiffusion in gel. The percentage variables were analyzed by GENMOD procedure and numerical variables were analyzed by ANOVA and differences were assessed using Tukey's test. 18.84% of the rams were positive against B. ovis. There was no difference in scrotal circumference and volume (P > 0.05) between positive and negative animals for B. ovis. Sperm concentration, mass motility, vitality, and the percentage of sperm with abnormalities, were modified in positive animals (P < 0.05), regardless of the presence of palpable lesions (P < 0.05). The percentage of rams with lesions in the epididymis and severe presence of somatic cells was higher in positive animals (P < 0.05). B. ovis infection adversely affects semen characteristics, due to an increase in epididymal lesions and by the severe presence of inflammatory cells in the ejaculate. Serological analysis to determine possible infection by B. ovis, should be considered as a component of the evaluation of fertility in rams, considering that sperm quality was affected in rams without lesions, but seropositive for B. ovis.