Heat Stress Management for Milk Production in Arid Zones

Arid and semi-arid zones account for one third of the earth's surface land area and cover most parts of the developing nations in the world including Latin America, Africa, and parts of India and South East Asia. Nevertheless, these ecosystems are not exclusive of developing countries because they also exist in developed nations such as United States of America, Spain, Australia, and Israel, among others. Arid zones are characterized by excessive heat loads and an insufficient and erratic pattern of precipitation. Also, actual evapotranspiration equals rainfall and recharge of groundwater is relatively infrequent. In general, summers are very hot and intense, but winters have commonly cold weather. In many countries with arid zones, high environmental temperatures during summer seasons may last up to 6 months, with average temperatures over 30°C. This is important because approximately one third of the cattle population in the world is located in arid zones, and according to IPCC predictions, the global average surface temperature may increase between 1.8 and 4°C by year 2100 (IPCC, 2007). The negative effects of global warming will be manifest in animal agriculture of both developed and developing countries, but the pressure will be greater on developing countries because of their deficiency of resources, their lack of veterinary and extension services, and their limitations on research technology development (FAO, 2007).