Sheep and goat milk in pastoral societies

Abstract Approximately 25% of the world's land surface supports about 20 million pastoral households or about 180–200 million people. Pastoral societies raise livestock often under extreme, extensive conditions on marginal rangelands that cannot be cultivated or used for other agricultural purposes. The animals provide the owners with milk, meat, wool/hair, leather and dung and, in addition, can be used as a source of cash, for transport and as pack animals. In most systems, several species of livestock are shepherded by pastoralists with sheep and goats being the most common and widespread. Traditionally, in pastoral systems in which sheep and goats were shepherded with cattle, cows were the main source of milk; when shepherded with camels, she-camels were the main source of milk; and when shepherded with yaks, naks were the main source of milk. Today, in general, the ratio of sheep and goats to other livestock is increasing, as is the ratio of milk produced by sheep and goats to other livestock. Sheep and goats raised by pastoralists are generally low-producing in terms of milk and offspring but are well-adapted to the climatic conditions and are relatively tolerant of local diseases. Goats generally produce more milk and have a longer lactation period than sheep, but sheep milk has higher fat and total solid contents than goat milk. Sheep produce about 40–60 kg of milk per lactation and goats up to 100 kg. In some areas, these small ruminants are particularly important for milk during the dry season and during droughts. Milk provides valuable products for pastoralists: butter and yoghurt for immediate consumption and storable ghee and dried curds for later use.