In the future all beasts of burden will have solar powered backs so that they can better serve man. Look how well it’s working out for the camel. The solar cells power a small refrigerator, which allows them to deliver heat-sensitive vaccines to remote health centers in Africa.
It’s an ingenious solution to getting them from point A to point B intact. When refrigeration isn’t needed, the solar system even provides lighting at the clinic. It’s win/win. Despite being in the desert, the sun doesn’t always shine and for those times they have a foot-powered generator.