The nature of the feed resource determines the type of livestock system which evolves in particular regions, and this in turn reflects the species of grazing animals which are best adapted to the physical and biological environment, and whose use meets the social and economic objectives of the farmers in that society. The level and quality of the feed supply is determined by climatic and edaphic factors, as modified by the intervention of the farmer and the plant species available.

The diverse livestock systems of the tropics may be categorised as those in which there is (1) close integration of animal production and the production of annual or perennial crops, (2) intensive ruminant production, (3) sedentary grazing based on planted or native pastures, or (4) nomadic pastoral activity. Grassland plays little part in pig and poultry production, which are not treated in this book.

Pastures in annual cropping systems

Significance

Payne (1976) estimated that c. 290 million cattle and buffalo are carried on mixed farms raising annual crops in the tropics. These farms are mostly operated by smallholders; in south-east Asia c. 90% of the ruminant population is found on mixed farms (Zandstra, 1983) which are less than 5 ha. Subsistence farming predominates; farmers' attitudes to risk are more cautious than those of more entrepreneurial farmers and are directed to ensuring that the family is fed.

The emphasis on the outputs from the crop or from livestock shows different patterns, and the objectives of the livestock operation have a varying balance between draught power, the rearing of young animals for sale, and the production of meat, milk and dung.