As the search continues for reliable chute-side tests for early signs of bovine respiratory disease (BRD), researchers work to identify indicators beyond gross signs, body temperature and other traditional methods of field diagnosis.
While the research is in its early stages, Jenna Funk, DVM, a resident veterinarian and post-doctoral researcher at Iowa State University, is exploring the potential for essentially a high-tech smell test for early detection of BRD pathogens. Funk and the ISU team theorized that plasma and/or nasal secretions from cattle in early stages of BRD could contain unique volatile organic compounds. Funk presented an abstract of the research at the recent Academy of Veterinary Consultants (AVC) summer conference.
The researchers note that metabolomics – study of how metabolites change due to disease or other influences – has shown potential for diagnostics in human and veterinary medicine.
For this research, the team collected 100 serum samples and 100 nasal secretion samples, half from healthy cattle and half from cattle showing signs of BRD. Criteria for identifying sick cattle included rectal temperatures of 104 or higher and Whisper (electronic auscultation) scores of 2 or higher. They used gas chromatography/mass spectrometry (GC-MS) to sample and analyze the air, or head space in sample vials containing .25ml of serum or nasal secretions.
In nasal swab samples, they found four compounds that differed significantly between sick and normal cattle, and in cattle serum samples they found five compounds that differed significantly. One compound, a phenol, differed significantly in both types of samples.
Funk says more research is needed, and the team is planning a case-control trial to begin this fall. Depending on research outcomes, volatile organic compounds could serve as biomarkers for use in quick and objective treatment decisions for cattle arriving in stocker or feedlot operations.
The open-access research report, titled Detection of volatile compounds emitted from nasal secretions and serum: Towards Non-Invasive Identification of Diseased Cattle Biomarkers,” is published in the journal Separations.
During the same AVC conference, West Texas A&M Animal Scientist John Richeson, PhD discussed the use of blood leukocyte differentials for chute-side BRD diagnosis. Read about that presentation in Predicting Disease Risk in Feeder Cattle.
AVC members can access the full recorded proceedings from every AVC conference, and qualify for continuing education credits. The proceedings are available on the AVC website or on mobile devices using an app developed by Kansas State University’s Beef Cattle Institute. The app is available from the Apple App Store or Google Play. Search “BCI Conference.”
The AVC’s winter 2018 conference takes place Nov 29 to Dec 1, at the Intercontinental Hotel, Kansas City, Mo.