Estimation of energy expenditures in horses and donkeys at rest and when carrying a load

In Morocco many farmers depend entirely on animal power to provide the energy required for producing their food and their crops. The main power sources controlled by farmers are usually equines. To promote animal power and allow more effective use of these animals, a large research programme dealing with hygiene, nutrition and management was developed. In the first part of the programme, a study was conducted on two horses and four donkeys to estimate the resting metabolism and to compare the oxygen consumption in the two species developing the same amount of work. The results showed that donkeys have a daily oxygen consumption at rest 20% lower compared to horses. In both species, walking for 8 h per day increased the daily energy expenditures by 60% and walking with a load for 8 h per day increased the daily energy expenditures by 70%. Nutritional recommendations can be made with respect to the time and the intensity of the work developed by animals.