We often hear that pen riding is as much an art as it is a science, and some pen riders seem to have a sixth sense for spotting the subtle signs of early stage respiratory disease. Systems based on human observation alone have limits though, as evidenced by continued losses to bovine respiratory disease (BRD) in spite of advancements in prevention and treatment options.
During the recent Academy of Veterinary Consultants conference, Edouard Timsit, DVM, PhD, outlined the application of various technologies for potentially improving early BRD detection and treatment success. Timsit is an assistant professor in cattle health at the University of Calgary and works with Feedlot Health Management Services, one of the largest feedlot consultant groups in North America.
Feedyards typically employ the D.A.R.T. system, which assesses depression (D), appetite (A), respiration (R) and temperature (T). Pen riders generally look for signs of depression in cattle behavior, along with more overt signs of BRD such as nasal discharge or high respiration rates. After removing suspect cattle to the hospital area, crews use rectal temperatures to confirm the presence of disease. By the time these signs are apparent though, disease often is well established, the animal's lungs and other tissues could be permanently damaged and treatment success is limited.
Veterinarians and cattle producers know that earlier detection correlates with treatment success, and Timsit says several technologies potentially can help identify sick cattle before they become apparent to the naked eye. In evaluating these systems, he says they first need to demonstrate accuracy in monitoring and measuring health parameters, such as physical activity, feeding behavior or body temperature. Then the user needs to determine the accuracy of that parameter in actually indicating or predicting sickness.
In a study in an Alberta feedlot, Timsit says researchers evaluated the sensitivity and specificity of measurements using rumen boluses for body temperatures, accelerometers for physical activity and RFID systems for recording feeding behavior. Each of the measurements helped detect disease, with rumen temperature showing the greatest accuracy and detecting disease up to 56 hours ahead of pen riders. Using all three measurements provided greater sensitivity than any single measurement or using any two in combination.
The REDI (Remote Early Disease Identification) system, from Precision Animal Solutions, also provide greater sensitivity and specificity than pen riders for detecting BRD. The REDI system combines aspects of feeding frequency, changes in activity patterns, and social interactions.
Timsit also notes that rectal temperatures alone, if below 105 F., do not always accurately identify BRD. Auscultation, used with rectal temperatures, can improve that accuracy. The Whisper electronic stethoscope, which provides objective scores for lung sounds, has shown high sensitivity and specificity in research trials, Timsit says.
For more information on AVC, and access to recordings of entire presentations at AVC conferences, visit AVC-beef.org.