Breeding soundness evaluation of bulls by semen analysis, testicular fine needle aspiration cytology and trans-scrotal ultrasonography

The aim of this study was to evaluate the usefulness of trans-scrotal ultrasonography and testicular fine needle aspiration cytology in assessing bulls for breeding suitability. These two techniques were also compared with semen analysis. Bulls presented for breeding soundness evaluation were assessed using all three techniques. The findings of each technique were compared. There was agreement in classification of fertile bulls using all three techniques, suggesting that the combined use of these techniques enhances routine breeding soundness examination. Use of the three techniques also enhances detailed investigation of suspected sub-fertile bulls while accurately identifying testicular cause(s) of sire sub-fertility.