Testicular degeneration, fibrosis, and mineralization in Limangus bulls

A group of Limangus heifers had a high pregnancy rate after timed artificial insemination but low final pregnancy rate after 75 days of natural service with 2 Limangus bulls. Bulls (A and B) suspected of subfertility and 2 other bulls (C and D) with the same genetic background were examined. Bull A was clinically normal but had no sperm in the ejaculate. Bulls B and C had abnormal testicular consistency resembling fibrosis on palpation and ultrasonography; however, semen was normal. Bull D was clinically normal. Bulls were negative for brucellosis and venereal diseases. Bulls A, B, and C were culled and slaughtered. Bull A had a normal genital tract; however, nonstructured 5B gene was detected by reverse transcription polymerase chain reaction, suggesting an infection with bovine viral diarrhea virus-1 (pestivirus A). Bulls B and C had macroscopic and microscopic signs of testicular degeneration, fibrosis, and mineralization. Although the specific cause for testicular lesions in bulls B and C was not identified, these lesions were probably responsible for the low pregnancy rate.