Ajustes asociados a la aclimatación y estrés oxidativo en ovinos bajo estrés calórico: una revisión

Abstract

Given the growing problem of global warming, sheep production is a feasible option to produce animal protein because of its heat tolerance. So sheep are one of the domestic species that possess a great adaptation to hot climates. This is possible due to the activation of different physiological, endocrine, metabolic and cellular adjustments to dissipate and decrease the production of body heat. However, the activation of these acclimation adjustments, coupled with the direct damage that high tempera-tures exert on cells, also causes oxidative stress. Increased respiratory rate and redistribution of blood flow to the periphery, as well as the release of cortisol and catecholamines, have been the main acclimation adjustments associated with an imbalance in pro and antioxidant activity. Thus, when an over-production of free radicals is generated, the structural and functional integrity of different cells and tissues is compromised, a circumstance that can compromise the welfare and productivity of sheep under hyperthermic conditions. Considering the above, the objective of this review is to present current information on the acclimation adjustments used by heat-stressed sheep and describe how they can be associated with the generation of oxidative stress.