Submitted to: Livestock Environment International Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: March 12, 2001
Publication Date: N/A
Interpretive Summary: Hot weather affects livestock and under extreme summer conditions can be life threatening. Managers need tools to deal with this problem. Body temperature and the rate of breathing are excellent indicators of stress and serve as tools to recognize moderate or severe conditions. Providing plenty of drinking water, timely feedlot cleaning and good airflow are generally adequate to assure survival. However, shade will provide additional protection. This study looked at the benefits of shade and used body temperature and rate of breathing to evaluate shade. There were reductions in both body temperature and rate of breathing during a portion of the study. The conclusion was that shade could reduce stress under hot, sunny conditions but may not be beneficial under normal summer conditions in the midwest.
Technical Abstract: Heat stress negatively impacts livestock production and under extreme summer conditions can be life threatening. Therefore, management tools are needed to help producers with intervention strategies in dealing with heat stress conditions. Respiration rate (RR) and core body temperature (CBT) associated with increasing environmental heat load could provide indicators sof thresholds useful in developing management strategies. Eight crossbred steers were assigned to individual feedlot pens during three separate four- day periods. The steers were randomly assigned to shade or non-shade treatments. Respiration rate was measured every 15 minutes and CBT every 30 seconds. Results indicated that shades significantly reduced CBT and RR, and also the reduced rate at which CBT and RR increased with temperature.