ABSTRACT
Livestock are a major source of support for the human populations of the arid and semi-arid zones. As well as providing meat, milk and wool, livestock also contribute indirectly to household income through their use as a source of energy, as a means of transport or through sales. We can distinguish two main types of economy in the zones receiving between 100 mm and 800 mm of rain a year. There are first, true pastoralists for whom more than 50 per cent of household income or more than 20 per cent of calories in their diet stem from livestock. A second group, agro-pastoralists, rely on animals for 10 to 50 per cent of their household income and therefore are dependent on other sources (agricultural production or wage labour, for example) for a part of their livelihood.
