To allow a comparison between different livestock herds, experts today employ the Tropical Livestock Unit (TLU), for which a TLU of one is equivalent to a 250 kg animal. A camel, for example, would give 1.0 TLU, while a sheep or goat would be equivalent to a TLU of 0.1. According to a study undertaken by the UK Department for International Development (DFID) in Ethiopia last year, for pure pastoralists to ensure minimum food security, a TLU of per capita of 3.0 must be maintained, guaranteeing sufficient stock for consumption and sales. To be economically independent, therefore, a pastoralist family of five would need a herd of at least 150 sheep and goats.