Near Infrared Spectroscopy as a Potential Method to Detect Bovine Respiratory Disease

Abstract

Bovine respiratory disease (BRD) continues to bethe leading cause of illness and death loss from weaning through finishing. There is no objective method to evaluate a live animal's severity of sickness or their response to treatment. A pilot study was conducted at a commercial feedyard to evaluate the ability of near-infrared spectroscopy to differentiate between cattle identified as healthy and those identified as having undifferentiated bovine respiratory disease. At processing, 215 randomly selected 900 lb (409 kg) heifers were evaluated to determine tissue oxygen saturation (StO2) levels. Mean ranks of the StO2 values were found to be 176.86+/- 5.50. One-hundred head of cattle pulled for clinical signs of bovine respiratory disease were evaluated in the hospital. Animals were classified as first pull, second pull and third pull based upon clinical observations. First pull animals were those with no previous history of being treated for respiratory disease and having signs of BRD with rectal temperature at or above 104 ° F ( 40° C). Second pulls and third pulls were those animals failing to respond to either a first treatment or a second treatment for BRD as evidenced by no improvement in clinical appearance or rectal temperature remaining above 104.0 F. Mean StO2 ranks were 110.42 +/- 11.29, 120.08 +/- 14.48 and 132.83 +/- 19.00 for first, second and third pulls, respectively. A significant difference was found between the rank of the StO2 values in cattle at processing and those classified as first, second or third pulls (P<0.05). No difference was found between the three pull classifications. The authors feel that the results shown in this study provide the basis for further research in the evaluation of BRD with near-infrared spectroscopy.