Physiological adaptability of livestock to climate change: A global model-based assessment for the 21st century

Abstract

Rising global temperatures and the growing world population create a paradox that compromises food security and hinders efforts to achieve the Sustainable Development Goals (SDGs) of zero hunger and climate action by 2030 Agenda. Global-scale studies are necessary to assess climate change scenarios in the livestock industry. Meteorological data and adaptive responses of animals reared in different countries around the world were used to show that animals in the thermal environment of the Northern Hemisphere must display a wider range of thermoregulatory responses than animals in the Southern Hemisphere. Subsequently, future climate simulations were performed based on conservative IPCC RCP4.5 climate models to project the impact of climate change on physiological responses of sheep, goats, dairy and beef cattle, pigs, poultry and quails, and identify key traits to strengthen the adaptative response to future climatic conditions. Results showed that ruminant animals in the Northern Hemisphere will be most impacted by climate change in the three climate scenarios of 2050, 2075, and 2100, with a predicted increase in respiratory rate of up to 68 % compared to animals in the Southern Hemisphere. Ruminant animals reared in the Southern Hemisphere will increase their rectal temperature as an adaptive response to climate change. It was also found that dairy cattle farming will be the most susceptible activity to heat stress in the coming decades in the Southern Hemisphere, and goats and beef cattle are the animals that will be less impacted by climate change due to phenotypic plasticity. Quails and laying hens will be the most susceptible animals to climate change, with respiratory rates expected to increase by up to 40 beats per minute by 2100. It is concluded that the adoption of animal adaptability protocols is becoming an increasingly relevant topic in livestock production systems in the Northern Hemisphere, with ongoing efforts to develop breeds and lines of domestic animals more resistant to heat stress and diseases, especially using resources locally adapted to the conditions of the Southern Hemisphere, where strategies should be based on the selection and crossbreeding to increase animal production and ensure food security for the growing population by the end of the century. For the poultry industry, intensifying the production system is needed and urgent since animals will not withstand high temperatures in systems with no environmental enrichment strategies. Finally, the conservation of locally adapted genetic resources will be essential to preserve biodiversity, strengthen ecosystem resilience, and address food security challenges in the face of climate change.