Impact of Stress on Health and Productivity of Animal: A Review

Abstract

Stress is any environmental change; including alteration in climate or management that is severe enough to elicit a behavioral or physiological response from the animal. The aims of this paper were to review the likely impact of stress on health and productivity of animal. Animals can be stressed by either psychological stress; restraint, handling or novelty or physical stress: hunger, thirst, fatigue, injury or thermal extremes. Thus, stressor can be any internal or external stimuli or threat that disrupts homeostasis of the body, and elicits a coordinated physiological response within the body in an attempt to reestablish homeostasis. The stress response includes several changes that may have negative effects on the health and performance of animals. These effects include changes in the immune function and increased susceptibility to disease, decreased feed intake and rumination, inhibition of oxytocin release, reduced fertility and effect on meat and by-product quality. Susceptibility to diseases can be increased as a result of situations which are likely to be stressful. For example, several studies have shown an increase in the prevalence of mastitis in dairy cows as a result of chronic fear. The effect of thermal stress on fertility is multifactorial in nature, since hyperthermia directly alters and impairs the cellular functions of various parts/tissues on other body functions like redistribution of blood flow among body organs, reduction in food intake, respiratory alkalosis. Thus to more research should be conducted on stress and its impact on animal health and productivity to design and implement possible prevention strategy.

Keywords: Animal health, animal productivity, stress