2009 Annual Report 1a.Objectives (from AD-416) Objective 1. Document the pathogenesis of BVDV in offspring of deer infected during pregnancy. Objective 2. Study the transmission of BVDV from persistently infected cervids to cattle. 1b.Approach (from AD-416) The overall goal of this application is the determination of the role of white-tailed deer as reservoirs of BVDV for domestic cattle. Our research objectives are: 1) Document the fetal pathogenesis resulting from BVDV infection of pregnant does. 2) Determine the ability of BVDV persistently infected deer to transmit BVDV to cattle or deer. To meet our research objectives we will infect pregnant white-tailed deer with BVDV in order to generate persistently infected (PI) fawns. To study transmission between cattle and deer we will expose BVDV naive cattle to fawns directly, to contaminated housing, or to contaminated feed. 3.Progress Report Pregnant deer, in the first and third semesters of pregnancy, were infected with a BVDV2 strains, isolated from deer, and pregnancy outcomes monitored. In addition, studies of transmission from deer to cattle by indirect contact following acute infection of deer were initiated. An abstract detailing these acute transmission studies was accepted for presentation at the 2009 American Association of Bovine Practitioners Meeting (Omaha, Nebraska, September 10-2, 2009).