Production, Management and the Environment: Heat Stress.

The article presents abstracts of various papers related to animal health that were presented during the symposium held on July 27, 2005 in Cincinnati, Ohio, which was organized by the American Dairy Science Association, the American Society of Animal Science, and the Canadian Society of Animal Science. One of the papers discussed is "Utilizing Data Loggers and Vaginal Temperature Data to Evaluate Heat Stress of Dairy Cattle," by M. Brouk, B. Cvetkovic, J. Smith, and J. Harner. Body temperature rise may indicate heat input has exceeded the heat exchange capacity of the dairy cow. Previous studies show a strong positive correlation between vaginal temperature and respiration rate. This indicates the stress response of the cow to increased body temperature. The ability to measure body temperature over time could help producers operate and select heat abatement systems. Another paper discussed is "Use of Physiological Measures As Predictors of Heat Dissipation During Heat Stress in Dairy Cattle," by B.C. Pollard, P.C. Gentry and R.J. Collier. The use of infared thermography to measure surface temperature is a very practical tool for dairy farmers to evaluate heat stress in dairy cattle. Data was compiled from three trials conducted in climatic rooms at the University of Anzona-Agricultural Research Complex.