Although donkeys play an important role in small farming in northern Cameroon, their feeding is neglected. A reasonably distributed economic domestic ration would reduce the morbidity observed and improve the productivity of these draught animals. This hypothesis justified setting up a nutrition trial to determine the rations of concentrate, straw and water required to cover their daily maintenance and work requirements according to the duration and intensity of effort. The feed used consisted of equal parts of cotton seed cake, brewery draff and maize bran. Performed during the hot dry season, the trial used groups of four adult male donkeys (105 kg live weight [LW]) and compared resting groups and working groups, It was divided into three successive periods: 1997 (5 weeks), 1998 (6 weeks) and 1999 (9 weeks). The working groups performed the same exercise with a weighted sledge on a farm track. Live weight, food consumption and ambient temperatures (dry and wet bulb) were monitored. The ration of provender required increased with the intensity of effort and was proportional to its duration. The experiment led to on-farm determination of the level of supplementation suitable for the intensity of effort required.