Rabbits eat grass and have hard poo; horses and cows have sloppy poo. Why?
Asked by Laura Young
While the rabbit, cow, and horse all have distinctly different digestive systems, the rabbit differs because it is required to ‘digest’ its food twice – they eat, poop, eat the poop and poop again. This is known as coprophagia. The first round of poo is very wet. But after they digest the food for the second time, it is dry – so they poo out pellets. Cows and horses do not have to eat their poo because they have other means of breaking down vegetation. Cows have very large, multiple-chambered stomachs that contain bacteria to help them break down the plant parts first time. The horse and the rabbit both have fermenting bacteria in their hindgut to help digest the fibre (cellulose) from plant matter. But because the rabbit’s intestinal tract is much shorter than that of the horse, it does not absorb nutrients as efficiently in one trip and thus needs to re-digest its food for a second time.