Adaptation des animaux d'élevage aux multiples contraintes des régions chaudes

Abstract

The question of adaptation of animals to the tropical environment has become a major challenge for the livestock sector and the scientific community. In harsh areas, the sustainability of farming systems is based on the ability of animals to survive, reproduce and maintain productivity under climatic, food or health constraints. In monogastrics and ruminants, the anatomical characteristics and feeding behavior are key factors regulating heat exchanges (small-size, decrease in subcutaneous fat mass, reduction in feed intake and physical activity). Level of basal metabolic rate, digestive efficiency, ability to utilize lower quality feeds, body reserves mobilization, nutrient recycling and water use efficiency are the main physiological traits of adaptation to underfeeding in ruminants. The most significant works on disease genetic resistance relate to trypanotolerance in African livestock, resistance to ticks or tick-borne diseases like heartwater and resistance to gastrointestinal strongyles. In modern farming systems, management of these environmental constraints must be considered in an integrated framework. Various feeding, environment and health management practices must be combined to reduce risk and maximize productivity. However, sustainable development of livestock production in tropical areas cannot be guaranteed without using the adaptation traits of native animal populations or at least without including adaptation traits in selection program for local and exotic breeds.