Project Number: 3040-32000-031-00-D
Project Type: In-House Appropriated
Start Date: Oct 1, 2011
End Date: Sep 30, 2016
1. Discover genetic and biological determinants associated with disease resistance to respiratory diseases of ruminants. 2. Discover effective intervention strategies to prevent and control respiratory diseases of ruminants. 3. Determine the impact of genomic components of antimicrobial resistance bacteria and cattle that impact bovine respiratory disease complex (BRDC) and develop intervention strategies to reduce antibiotic use. 3a. Identify antibiotic-resistance genes and other virulence determinants of bacteria that associate with increased BRDC severity. 3b. Identify bovine genomic variation that associates with reduced BRDC susceptibility. 3c. Develop intervention strategies to reduce antibiotic use and BRDC severity based on genetic typing of bacteria and cattle.
Infectious respiratory diseases of ruminants are a serious health and economic problem for U.S. agriculture. In cattle alone, bovine respiratory disease complex (BRDC) costs the feedlot industry approximately 1 billion dollars annually. Accordingly, this research focuses primarily on BRDC with an additional component targeting ovine respiratory disease. These diseases result from host, pathogen and environmental interactions that are incompletely understood. We propose studying these interactions to identify intervention points for producing healthier livestock. For example, failure of passive transfer (FPT) has genetic and environmental components that predispose calves to BRDC. A genome-wide association study will be used to test for FPT genetic risk factors. Also, the predominant pneumonia associated with BRDC is caused by Mannheimia haemolytica. Transcriptome profiling will be used to identify host cellular responses to this pathogen. BRDC research requires development of species-specific tools, thus monocyte cell lines will be developed. Also needed are early indicators of BRDC outbreaks. Changes in the viral metagenomes (VMs) of cattle will be evaluated as potential early indicators of infection. Finally, genetic risk factors for ovine progressive pneumonia (OPP) will be tested as a model for preventing respiratory diseases of ruminants. A reduction of the prevalence, severity and/or treatment of respiratory diseases would enhance producer efficiency and promote the welfare of livestock. This research fills critical gaps in our knowledge of ruminant respiratory disease and could ultimately benefit regulatory agencies, animal health companies, veterinarians, and livestock producers that need information and new approaches for controlling respiratory disease.