A study of using donkeys in harrowing operation was undertaken. Experiments on three work-rest schedules and their effect on physiological response of the animals were studied. Among the three schedules, namely 1 hour work, 1 hour rest - 1 hour work - 1 hour rest - 1 hour work - rest was found to be the best. During this schedule the field capacity (0.151 ha/hr) and the power out put (0.31 kW) were found maximum.