Resource requirements for draught animal power

the next most important and are found mainly in Asia, particularly in the wetter, more humid areas. Donkeys, camels, horses, mules, yaks, llamas, and even sheep and goats are also used for work in a variety of different operations from transport and cultivation to harvest operations and water lifting. Animal power probably makes its greatest contribution in agriculture although animal use for transport is extremely important. Draught animals provide proportionately about 0.8 of the power input on third-world farms. In fields which tractors cannot reach, such as terraced hillsides or muddy river valleys and on farms where size and scale of enterprise as well as finance rule out the purchase of tractors, then animal power is the only means that the farmer has of cultivating his land, other than hand labour. The place of draught animal power on farms in tropical agriculture is discussed. In some areas of the world draught animal power is traditional, in others it is a relatively neu' technology. There are situations ulhich fall betu'een the two, but ulhen thinking about resolving technical and more particularly socio-economic constraints it is o.tten useful to be au'are of these two categories. While some of the problems encountered are universal, other problems can be more specific to a particular situation or country. In this paper some of the issues are discussed. These include the energy requirements for work, the provision of food, particularly in 'neu" draught animal areas, the consequences of using draught cows in traditional systems, disease treatment and two examples of country specific problems. In some cases strategies to cope with these issues are available, largely as a result of research, in others it is apparent that more information is required. Introduction The use of draught animals to provide power in agricultural systems provides one of the most remarkable interactions between crops and livestock. Draught animals need 'fuel' in the form of chemical energy from crops and forage to work, but in many areas in order to produce a crop successfully animal power is required. One cannot do without the other. Where animal power is used the amount of work an animal is capable of doing ultimately affects the area cropped and the yield per farm, particularly where growing seasons are short. Animal power is used in virtually every environment and in every continent in the world, and constraints depend very much on location and the type of animal being used. Patterns of draught animal use in agriculture There are many areas of the world where traditional draught animal power is now being replaced by mechanized power. In parts of East Asia mechanization has been rapid over the last 10 to 15 years (Watanabe, Muramatsu and Oishi, 1985; Siriweera, 1989) and tractor use has for example, more than doubled from 1975 to 1985 in China, India, Malaysia and Vietnam (Campbell, 1989). Nevertheless, there are many situations, where it is difficult to see farmers ever being able to adopt mechanical power to replace animal power. In several areas in Africa and Latin America the trend is for farmers to compromise. Those who can afford to do so are using tractors alongside animals. The tractor for instance may be hired for hard work such as ploughing and then the farmers use their own animals for secondary cultivation, seeding, weeding and harvesting the crop. This usually proves to be an excellent compromise, with the difficult jobs being accomplished quickly, but without the farmer having to incur a large debt investing in an expensive tractor. The farmer still has Oxen are numerically the most important draught animals, being common on small farms in Africa, Asia and parts of Latin America. Water buffalo are