title: Water requirements for livestock production: a global perspective.
abstract: Water is a vital but poorly studied component of livestock production. It is estimated that livestock industries consume 8% of the global water supply, with most of that water being used for intensive, feed-based production. This study takes a broad perspective of livestock production as a component of the human food chain, and considers the efficiency of its water use. Global models are in the early stages of development and do not distinguish between developing and developed countries, or the production systems within them. However, preliminary indications are that, when protein production is adjusted for biological value in the human diet, no plant protein is significantly more efficient at using water than protein produced from eggs, and only soybean is more water efficient than milk and goat and chicken meat. In some regions, especially developing countries, animals are not used solely for food production but also provide draught power, fibre and fertiliser for crops. In addition, animals make use of crop by-products that would otherwise go to waste. The livestock sector is the fastest-growing agricultural sector, which has led to increasing industrialisation and, in some cases, reduced environmental constraints. In emerging economies, increasing involvement in livestock is related to improving rural wealth and increasing consumption of animal protein. Water usage for livestock production should be considered an integral part of agricultural water resource management, taking into account the type of production system (e.g. grain-fed or mixed crop-livestock) and scale (intensive or extensive), the species and breeds of livestock, and the social and cultural aspects of livestock farming in various countries.
authors.affiliation: Joint Food and Agriculture Organization of the United Nations (FAO)/International Atomic Energy Agency (IAEA) Division, Department of Nuclear Sciences and Applications, Wagramer Strasse 5, P.O. Box 100, A-1400 Vienna, Austria.
authors.forename: A C
authors.initials: AC
authors.lastname: Schlink
authors.forename: M L
authors.initials: ML
authors.lastname: Nguyen
authors.forename: G J
authors.initials: GJ
authors.lastname: Viljoen
mesh_terms: D000822:Animal Husbandry / Q000592:standards*; D000818:Animals; D004044:Dietary Proteins / Q000600:supply & distribution; D004326:Drinking / Q000502:physiology*; D020387:Food Chain; D006801:Humans; D038622:Internationality; D058751:Livestock / Q000502:physiology*; D010945:Plants, Edible / Q000502:physiology*; D014881:Water Supply / Q000191:economics / Q000592:standards* / Q000706:statistics & numerical data
chemical_list: D004044:Dietary Proteins