They’re herbivorous ungulates. They’re nonruminant so you’ll need to be real careful about not giving them enough. Their cellulose breakdown is pretty inefficient. I’d recommend a good few hundred pounds of feed. If you want an in-depth nutritional plan, I’d recommend googling a race horse’s recommended diet and amplify it by a good amount.
I wonder if their digestive system is ass-backwards like the horse’s…
I’ma google this.