Bovine Viral Diarrhea Viruses (BVDV) in Beef Breeding Herds and Feedlots

Abstract

Bovine viral diarrhea viruses (BVDV) represent significant pathogens in cattle affecting several organ systems, particularly involving the respiratory tract and fetal infections. The principal reservoir of BVDV is the persistently infected (Pl) animal. The PI cattle are born to susceptible heifers/cows exposed during pregnancy, carried to term, and are lifetime shedders of the virus. Current control programs focus on biosecurity using testing of new additions including calves born to negative dams, isolation of new animals until testing completed, and vaccination. Identification by testing and removal of PI cattle are critical to control programs. PI cattle may expose susceptible breeding females resulting in more PI calves; and/or cause primary infections in acute/transient infections and predispose the BVDV exposed animal to other pathogens. The purpose of this study was: (1) detect PI cattle in beef breeding herds and cattle entering feedlots; and (2) determine distribution of BVDV subtypes in PI cattle.