Assessment of fatigueness in donkeys during different sets of workload

Adult Large White donkeys (6) were selected for this study and they were maintained under ideal housing and feeding conditions for the entire experimental period. Donkeys were hitched (in pair) for light work (load of 10% of body weight), moderate work (load of 20% of body weight) and heavy work (load of 30% of body weight) for 2 h work/day during morning hours. Each experiment was repeated with same work schedule for 5 days. Fatigue score was calculated based on the physiological responses such as respiration rate (RR/min), pulse rate (PR/min) and rectal temperature (RT in degrees C) and behavioural symptoms such as leg incoordination, tongue protrusion, excitement, frothing, sweating and panting. The fatigue scores were 0, 5 and 9 during first hour, and 6, 10 and 18 during second hour of work in light, moderate and heavy work respectively. This indicated that animals did not fatigue during first and second hour of work with a load up to 20% of their body weight. However they showed symptoms of fatigueness only at the end of second hour during heavy work (at a load of 30% of their body weight). In all the experiments the RR, PR and RT increased significantly (P<0.05) as work load and duration of work increased which finally resulted in the elevation of fatigue score. Hence it may be concluded that large white donkeys can work with a load of 20% of their body weight for 2 h comfortably without showing fatigueness but at a load of 30% of their body weight they can work only up to 1 h.