June 04, 2018

Interpretive Summary: Evaluating the Microbiome of Two Sampling Locations in the Nasal Cavity of Cattle with Bovine Respiratory Disease Complex

Interpretive Summary: Evaluating the microbiome of two sampling locations in the nasal cavity of cattle with bovine respiratory disease complex (BRDC)

By: Dr. Caitlin Vonderohe

calfBovine respiratory disease complex (BRDC) is the most expensive disease affecting the U.S. beef industry. An animal’s likelihood of being infected with BRDC is related to commensal bacteria that normally inhabit the animal’s nasal cavity. Therefore it is important to properly sample the bacteria present in the nasal cavity to be able to identify animals that are more likely to be affected by BRDC. The objective of “Evaluating the microbiome of two sampling locations in the nasal cavity of cattle with bovine respiratory disease complex (BRDC),” published in the April issue of the Journal of Animal Science, was to compare bacterial populations found using two different bacterial sampling techniques of the bovine nasal cavity.

The researchers used two different types of swabs to sample the nasal cavity: deep nasopharyngeal swabs and 6-inch nasal swabs. The deep nasopharyngeal swabs are guarded against contamination and are therefore wider than 6-inch swabs, making their use more stressful for the calves. These swabs are also more expensive than the 6-inch nasal swabs. The authors wanted to see if there is a difference in the bacteria sampled using the two types of swab. The 6-inch swabs sampled approximately 6 inches into the nasal cavity and the deep pharyngeal swab sampled 8-inches into the nasal cavity and pharynx. Calves of that had previously been diagnosed with BRDC and control calves were sampled using both types of swabs at different ages to show how the bacterial populations change as the animal ages. DNA was extracted from each swab, then amplified and sequenced, using next-generation sampling techniques to identify the bacteria present from each sampling location.

The authors found that bacterial populations are similar between the deep and nasal sampling sites. The data also showed which bacterial populations are associated with Bovine Respiratory Disease complex. The authors also noted that bacterial populations associated with BRDC change when animals are weaned and age. The authors concluded that the less-invasive 6-inch swabs can be used to evaluate calf susceptibility to BRDC, and this susceptibility can be assessed based on the bacterial populations associated with BRDC described in the paper. This is significant because the use of 6-inch swabs can reduce stress on animals during sampling. In experimental situations, the use of the less-expensive swab could allow sampling of a greater number of animals, resulting in more statistical power in research and more efficient experiments.

To view the full article" Evaluating the microbiome of two sampling locations in the nasal cavity of cattle with bovine respiratory disease complex (BRDC)," visit the Journal of Animal Science