Genetic approaches to investigate animal adaptation to climate change

Climate change is expected to adversely impact livestock production across the world, with a magnitude of effects that will differ from one region to another. In the South (Mediterranean and tropical areas) climate constraints are already important and will worsen in the near future. In the North increased frequency and intensity of extreme weather events (floods, droughts, dry spells and heat waves) are expected. Improving the adaptation of livestock to climate related stressors is a requirement to meet the challenge of a growing human population. Most direct effects of climate change on animal health, production and wellbeing are related to global warming, which further accentuate heat stress related problems. Animals highly selected for production traits perform the best in industrial production systems where the environment is stable and adapted to the animal?s needs. This standardization of the production environment has made these animals particularly vulnerable to environmental perturbants such as increased environmental temperatures. There is evidence that animal response to high temperature is under genetic control, including single genes of major effects as well as complex polygenic components, giving the opportunity to improve the animal?s thermal tolerance using genetic and genomic tools. Considerable variation exists for heat tolerance between breeds and within individuals of the same breed that may be evidenced by environmental genomic studies taking into account a wide range of production environments. Selection for quantitative traits related to thermal adaptation could also increase animal heat tolerance; however, because of the antagonism between productivity and robustness, this selection must be done with care, without major negative impact on production potential.