This week we took some of our first year Animal Behaviour and Conservation Biology students to watch a Dartmoor Pony (Equus ferus Boddaert) dissection at Dartmoor Zoo, which is a relatively short drive from the University and is just on the south tip of Dartmoor, surrounded by beautiful countryside. Dartmoor ponies are an essential part of the moor’s ecosystem and are semi-feral at present. In order to conserve the moor’s ecosystem, it is vital that the ponies are preserved in a viable and healthy state. Because of the small gene pool getting even smaller, there is a scheme under way to cull individual female ponies that consistently deliver deformed or ill foals. This sounds quite an extreme means to deal with the problem but it’s really the only way.

To ensure this is a waste-free process, once the animals have been slaughtered, the zoo butchers the meat for use as feed for zoo animals such as tigers and lions. They also enjoy the occasional horse’s head but the public tends not to like to have to see that, so it’s kept to an occasional treat! The skin is used for leather or to make toys for the big cats to train with - as are the tails. The bones and offal are sent to be rendered into tallow and gelatine for non-human use, such as in laboratories.

In this photo, the underside of the horse has been opened and the digestive tract is spilling out. The bright yellow matter is adipose (fat) tissue under the skin of the pony. The large structure hanging to the floor is the cecum - in humans this is a small pouch at the junction of the small and large intestines, but in some animals like this pony that eat a lot of cellulose (in plant material), the cecum is much larger. This is because it is the location in which hind-gut fermentation takes place, where anaerobic Bacteria ferment cellulose to enable it to be digested. 

Simply put, without its cecal Bacteria, this horse would not be able to survive on its diet of grass and plant matter since it would not be able to digest the cellulose present at all.