Adapted by Betsy Karle - UCCE Dairy Advisor, Northern Sacramento Valley
Sharif Aly, BVSc, MPVM, PhD - UC Davis Veterinary Medicine Teaching & Research Center
The problem
Bovine respiratory disease (BRD) is a disease of major economic importance to the dairy industry in California and across the United States, resulting in losses in excess of $700 million annually. However, BRD remains difficult to detect, leading to poor treatment outcomes, suboptimal animal welfare, and sometimes unnecessary antibiotic use. Diagnostic challenges arise because the specific clinical signs presented by calves with BRD are widely variable, and there are no clinical signs that are always present in affected animals. Management practices to reduce the incidence of BRD have been similarly misunderstood. Since BRD can be caused by environmental, bacterial or viral agents, it has been unclear where we should focus management efforts to reduce this disease. While we knew much about how to prevent the disease through the basic mechanisms of improving a calf’s immunity, be it through better colostrum management, feeding or vaccination, we really didn’t have a quantitative understanding of how the daily management of calves and their dams can modify a calf’s risk for BRD.
What have we done?
Researchers in UC Cooperative Extension, the UC Davis School of Veterinary Medicine and the California Department of Food and Agriculture worked together to develop a clinical scoring system and mobile application to detect BRD in preweaned dairy calves that you have read about in this newsletter before (see November 2014, October 2015, and January 2017 issues). We then visited 100 dairies throughout the state to survey management practices and estimate BRD prevalence in over 4,600 calves using the newly developed scoring system. These management practices were analyzed to determine their association with BRD prevalence on different dairies. With this information in hand, the team followed over 10,000 calves on six different dairies from birth to weaning, keeping careful records on cases of BRD and associated management practices. All of this data has been compiled and analyzed, identifying important management practices that can help reduce BRD in young calves.
Now what?
With this information, we have successfully identified the primary risk factors for BRD in young dairy calves and are working on finalizing a risk assessment tool to help manage this complex disease on dairies. This tool will help producers assess the risk of BRD in calves on a dairy in a comprehensive way, producing a road map that can be used to make the needed changes to control this costly disease in preweaned dairy calves. The assessment will rely on a questionnaire with specific sections and the questions will be linked to scores for each management practice associated with BRD in calves, based on the earlier studies. The combined risk assessment with scores will make the tool one that can be used by consultants, veterinarians or producers to assess the risk of BRD on a specific herd, which in turn is used by the dairy farmer to identify areas where management is deficient (low score) in prevention and control of BRD. We will be rolling out the risk assessment soon. Please contact us (bmkarle@ucanr.edu or saly@ucdavis.edu) if you are interested in helping beta test the first version.
To learn more about how to use the mobile application, effective ways to manage BRD in your calves, and so much more, attend the 2018 Golden State Dairy Management Conference, March 29-30, in Stockton!
Link to PDF Version: Improved Detection and Management Reduces Respiratory Disease in Dairy Calves