Tami M. Brown-Brandl
Dr. Brown-Brandl is an agricultural engineer whose research focus is on development of information to assist livestock producers in making decisions about management of livestock to cope with climatic stress. Temperature and humidity controlled environmental chambers and calorimeters are available to investigate the impact of the thermal environment on livestock. Physiological measures of body temperature, respiration rate, feed consumption and heat production are the primary measures of dynamic animal response to stressors. Production data such as feed intake and growth rate provide response data familiar and important to producers. In addition to feeding behavior, other behavioral measures are used to evaluate the behavioral response.
Within the feedlot, climatic variables of temperature, humidity, wind speed and solar radiation have been shown to directly affect an animal’s responses but physical characteristics of the animal such as hair coat color, body condition and adaptation are also important. In addition, an animal’s health history and temperament will impact the importance of thermal stressors. Feed delivery and composition can provide some level of management strategy as well as providing some level of specialized care such as shade, sprinkling or forced air movement.
Successful management of stress requires knowledge of the importance of stress, identification of stressful conditions, being prepared to ameliorate the stress and taking appropriate action when necessary. Management of this mixture of physical, physiological and behavioral approaches to rearing cattle can be guided through use of prediction models incorporating the impact of each of these factors. Development of such a model is in progress.