The value of global livestock production in 2013 has been estimated at 883 billion dollars, (constant 2005–2006 dollars). However, economic implications of livestock production extend further: to downstream industry (saleyards,
abattoirs,
butchers, milk processors, refrigerated transport, wholesalers, retailers,
food services,
tanneries, etc.), upstream industry (feed producers, feed transport, farm and ranch supply companies, equipment manufacturers,
seed companies,
vaccine manufacturers, etc.) and associated services (
veterinarians, nutrition consultants, shearers, etc.). Livestock provide a variety of food and non-food products; the latter include leather, wool,
pharmaceuticals, bone products, industrial protein, and fats. For many
abattoirs, very little animal biomass may be wasted at slaughter. Even intestinal contents removed at slaughter may be recovered for use as fertilizer. Livestock manure helps maintain the fertility of grazing lands. Manure is commonly collected from barns and feeding areas to fertilize cropland due to its nutrient rich content, however, can pose some biosecurity and health risks. In some places, animal manure is used as fuel, either directly (as in some non-Western countries), or indirectly (as a source of methane for heating or for generating electricity). In regions where machine power is limited, some classes of livestock are used as draft stock, not only for
tillage and other on-farm use, but also for transport of people and goods. In 1997, livestock provided energy for between an estimated 25 and 64% of cultivation energy in the world's irrigated systems, and that 300 million draft animals were used globally in
small-scale agriculture. Although livestock production serves as a source of income, it can provide additional economic values for
rural families, often serving as a major contributor to
food security and
economic security. Livestock can serve as insurance against risk and is an economic buffer (of income and food supply) in some regions and some economies (e.g., during some African droughts). However, its use as a buffer may sometimes be limited where alternatives are present, which may reflect strategic maintenance of insurance in addition to a desire to retain productive assets. Even for some farmers in Western nations, livestock can serve as a kind of insurance. Some crop growers may produce livestock as a strategy for diversification of their income sources, to reduce risks related to weather, markets and other factors. Many studies have found evidence of the social, as well as economic, importance of livestock in non-Western countries and in regions of
rural poverty, and such evidence is not confined to pastoral and
nomadic societies. Social values in developed countries can also be considerable. For example, in a study of livestock ranching permitted on national forest land in New Mexico, US, it was concluded that "ranching maintains traditional values and connects families to
ancestral lands and
cultural heritage", and that a "sense of place, attachment to land, and the value of preserving open space were common themes". "The importance of land and animals as means of maintaining culture and way of life figured repeatedly in permittee responses, as did the subjects of responsibility and respect for land, animals, family, and community." In the US, profit tends to rank low among motivations for involvement in livestock ranching. Instead, family, tradition and a desired way of life tend to be major motivators for ranch purchase, and ranchers "historically have been willing to accept low returns from livestock production". ==Environmental impact==