1 OPTIONS FOR MANAGING LIVESTOCK PRODUCTION SYSTEMS TO ADAPT TO CLIMATE CHANGE E. N. Sossidou 1 , E. Tsiplakou 2 and G. Zervas 2 1 Veterinary Research Institute, Hellenic Agricultural Organization-DEMETER, Thessaloniki, Thermi, 57001, Greece 2 Nutritional Physiology and Feeding, Agricultural University of Athens, Athens, 11885, Greece Presenting author email: sossidou.arig@nagref.gr, Tel.: 0030 2310 365383, Fax: 0030 2310 365371 Abstract Climatic conditions determine the energy and nutrient metabolism of farm animals and have a major influence on livestock heath, welfare and performance. There are upper and lower critical temperatures for different animal species and age groups. Reducing thermal stress in animal production remains a topic of concern with producers and scientists alike. In order to limit the impact of extreme climate events in the long run, the most important measure consists in implementing preventive means at the level of the farming system itself. This paper discusses recent research findings together with management schemes in preventing and managing of thermal stress by handling external and internal factors in livestock production systems. Preventive measures against thermal stress are described as basic structural adjustments and the modifications that can be implemented readily, according to animal health and welfare requirements and refer to (a) environmental modification and thermal comfort in various housing systems: pasture management, ventilation, stocking densities, resting pens, waste management, etc; (c) action on animals: genetic selection for breeds resistant to infectious disease, parasites and climate extremes, reproduction management, etc; (d) action on feed: feeding schemes, supplements and additives, vitamins, minerals, etc; and (e) action on staff: handling animals, milking, sharing, etc. Moreover, measures to be taken both in situations of chronic thermal stress and heat or cold strokes are presented as they are applied to (a) limit stress, (b) monitor the temperature felt by animals, (c) adapt diet and drinking water supplies and (d) correct physiological imbalances. Examples are given for different farm species (cattle, sheep, goat, poultry and pigs) and different production systems (intensive, extensive, alternative). The paper concludes with a practical guide for the effective handling of thermal stress at farm level, summarizing the results from recent research studies on the specific topic. Keywords Livestock production, management, thermal comfort 1. Introduction Recent data and model predictions suggest that the climate changes will result in more extreme weather in different parts of the world leading to frequent changes of hot and cold temperatures. It appears reasonable the livestock sector to come up with new strategies in order to maintain and increase the production potential under altered climatic conditions. Climatic conditions determine the energy and nutrient metabolism of farm animals and have a major influence on livestock heath, behavior, welfare and performance. There are five ways in which an animal may exchange heat with its environment: solar (shortwave) radiation gain, long wave radiation exchange, convective exchange, conductive exchange, and heat loss by evaporation. This heat exchange, in combination with the metabolic heat produced by the animal, defines the animal’s heat balance. When a homeothermic animal cannot lose sufficient body heat (generated by metabolism, or gained from the environment) to maintain a stable body temperature, the animal experiences heat stress. In a cold environment when the same animal losses heat to the environment faster than metabolic heat is generated, or heat is gained from the environment, the animal experiences cold stress. Under conditions of heat stress, animals may seek a cooler environment in the shade, while under conditions of cold stress animals find relief by sheltering from wind, rain and snow [1, 2]. When an animal’s microenvironment ventures outside its thermoneutral zone, a portion of the metabolizable energy typically used for production must be diverted to assure thermal balance. Direct effects include altered production, reproduction and resistance or susceptibility to disease. Indirect effects involve