• horse;
  • donkeys;
  • exercise;
  • conditioning;
  • lactate


Five healthy standard donkeys were subjected to exercise tests on a treadmill before and after conditioning. After the pre-conditioning trial, the donkeys worked 3 days/week for 60 min pulling a cart at increasing trot duration and 2 days/week for 20 min in a round pen for the 28 day conditioning period. During the trial, donkeys worked at 1.5–2 m/s on an 11% grade for a distance of 1830 m. Heart rate, respiratory rate and body temperature were recorded before, 10 min into exercise, immediately following and 1, 5, 10, 20, 30, and 60 min after exercise. Arterial samples for blood gas measurements and venous samples for measurement of lactate [La], glucose and triglyceride concentrations also were collected.

Mean blood [La] in unconditioned donkeys increased from 1.25 mmol/l at rest to 3.48 mmol/l at 1 min after exercise. Conditioning resulted in decreased heart rate and lactate and blood glucose concentrations during recovery. There were no effects of exercise or conditioning on triglyceride concentrations or blood gas values.