Читать книгу Bovine Reproduction - Группа авторов - Страница 191

The introduction of replacement bulls into the cow herd represents a significant risk for disease introduction. The primary pathogens of interest in the USA include Brucella abortus, Campylobacter fetus subsp. venerealis, Tritrichomonas foetus subsp. venerealis, Leptospira species, Mycobacterium avium subsp. paratuberculosis, Mycobacterium bovis, BVDV, and BHV‐1.

In addition to diagnostic screening for potential pathogens, all replacement bulls should be quarantined for a minimum of 30 days before exposure to the cow herd. This period will allow viral shedding to cease in bulls with acute BVDV and BHV‐1. Producers should also be aware that no diagnostic test is 100% sensitive and therefore bulls should be purchased from herds with good health programs. Purchasing bulls from herds that are certified free for a specific pathogen provides additional security. Likewise, purchasing virgin bulls eliminates the risk for C. fetus and T. foetus.