ABSTRACT
Livestock production, one of the most important agricultural subsectors worldwide, is practiced in rangeland areas and in mixed crop-livestock systems that cover about 60% of the land area of developing countries [well established]. In developing countries cattle, sheep, and goats total about 1.2 billion tropical livestock units (converted at the rate of 250 kilograms of live animal weight per tropical livestock unit). Animal densities are strongly correlated with human densities and are highest in areas of intensified agriculture, especially in and around irrigation systems. Animals are heavily dependent on water for feed production, using an estimated 500 billion cubic meters or more a year for maintenance. Total water needed may be more than double this amount, with drinking water less than 2% of that required for feed production. Inappropriate grazing and watering practices contribute to widespread degradation of water and land resources, particularly around watering sites. Investments in water and livestock have often failed to achieve maximum and sustainable returns because of a lack of integration of the two.
