Student Case Presentation
The Association Between Adrenal Gland Weight and Bovine Respiratory Disease Chronicity in Feedyard Cattle: Implications for Stress Assessment
| Date/Time: |
9/11/2025 4:15 pm
|
| Presenter: |
Katherine Gates |
| Veterinary School: |
FL |
Abstract:
Chronic stress in feedyard cattle is a major concern, impacting health and performance. Adrenal gland hypertrophy is a known physiological response to prolonged stress, yet its relationship with disease progression remains unclear. While live-animal stress biomarkers such as cortisol require laboratory analysis, adrenal gland weight at necropsy may provide an immediate indicator of chronic stress. This study aimed to assess the association between adrenal gland weight and bovine respiratory disease (BRD) chronicity in necropsied feedyard cattle. Adrenal glands and kidneys were collected from 107 feedyard cattle at necropsy. Cattle were classified as having either chronic or acute BRD based on gross pathological findings. A statistical linear regression model was used to evaluate the relationship between BRD chronicity and adrenal gland weight, with kidney weight included to account for individual size variation. Preliminary results did not identify a significant association between adrenal gland weight and BRD chronicity (P > 0.05). The average adrenal gland weight for cattle diagnosed with chronic BRD was 15.69 ± 0.51 grams, while those with acute BRD averaged 14.87 ± 1.94 grams. These findings suggest that adrenal gland weight alone may not reliably indicate chronic stress associated with BRD. While adrenal hypertrophy has been linked to prolonged stress responses, its utility as a post-mortem marker of chronic BRD stress remains uncertain. Further research incorporating additional physiological and biochemical stress markers may provide a more comprehensive understanding of chronic stress and its impact on cattle health.
