RESUMEN
The economic contribution of draught animals to smallholder Mazahua campesino systems in two mountain villages of San Felipe del Progreso, in the central highlands of Mexico, was assessed. Campesinos rely on draught animals for cultivation tasks, as pack animals, and as transport for agricultural and domestic activities. The villages were San Pablo Tlalchichilpa (SPT) and La Concepción Mayorazgo (LCM). Twelve households that possessed draught animals were monitored from July 1999 to June 2000, nine in SPT and three in LCM, in terms of animal inventories and income from their draught animals, in cash and opportunity values. Equines in SPT have substituted bulls, and are recognized for their multipurpose contribution, while in LCM bulls are still used for ploughing the land. Overall total mean gross income was US dollar 490.78 per farm per year, plus US dollar 56 as opportunity value of the fertilizer value of manure for both villages. Deducting estimated costs, owning draught animals leaves a mean net margin of US dollar 412.50/year in SPT and of US dollar 285.64/year in LCM. There is a significant correlation (p < 0.05) between ownership of draught animals and incomes, with a regression coefficient of US dollar 279.16 per year per draught animal. Besides positive economic returns, having work animals alleviates drudgery for the campesino families.