In the summer of 2016, three pack mules, each carrying a load weighing 80kg, accompanied a 94.46km trek across the Gotthard Pass with a total altitude difference of 3,364m. The mules’ performances were evaluated by measuring vital recovery parameters such as heart- and respiratory rates and body temperature, and by continuous heartrate monitoring during the trek. The stress levels of the animals were estimated by determining glucocorticoid metabolite levels in their faeces. Throughout the trekking days, recovery heartrates lay within a range which indicated that the animals were not being overworked. The continuous heartrate monitoring of one of the mules showed that its physical performance lay within the endurance zone. As expected, glucocorticoid metabolite levels were elevated in the faeces of all the mules – a normal physiological response after five consecutive days of exercise. The study shows the mules as being capable of performing at an endurance level during the Gotthard trek with no adverse affects on their health – a performance which was historically expected of the animals.
Performance and stress level in mules during a five days Gotthard trek