Biological and Behavioral Indicators of Stress in the Boar

Purdue University 1997 Swine Research Report. With the advent of increased public awareness and appreciation for animal well-being in livestock production, it is becoming necessary to understand more specifically how animals perceive different situations and assess whether or not their well-being is being met. This is necessary to maintain a level of public respect for current production practices and to enhance the image of livestock production in the United States and worldwide. Through greater scientific understanding of the animals perception of environmental stimuli and of animal cognition, production facilities and management practices could be altered to meet the needs of the animal, and thereby enhance well-being. In order to fully understand the status of well-being in an animal, we must first identify some indicators of well-being in that animal. Because we are unable to do direct evaluation of any mental sufferings that might be present in the animal, we are forced to utilize other indicators such as physiological, immunological, behavioral, and anatomical indicators of stress and distress. Most researchers agree that low levels of stress are beneficial for animals because they allow them to maintain a homeostatic balance of their physiological systems. It is only when the perception of stressors becomes so great that it affects normal functioning and production of the animal that we utilize the term distress. Stress cannot simply be measured by a single variable but instead must be evaluated based upon several criteria, which will provide information to distinguish the good stress from the bad stress. The objective of this experiment was to gain a greater understanding of how boars physiologically respond to different, and presumably stressful, situations. Specifically, it was hoped to discover a measurable difference between stressful experiences which could be described as being a good stress and those which could be described as being a bad stress.