A rump. They are the hind quaters (near the tail).
It is usually refered to as the hind leg. The parts of the hind leg are the hip, stifle, gasgin, hock, fetlock, pastern and hoof.
They're called the back legs
You call them the front legs ;)
A horses leg is called a leg, but it has several names for different areas of the leg like cannon, hock and gaskin.
The stifle joint
The rear leg of a pig is called a ham.
They are called hock boots and they are worn to protect th horses leg when jumping.
It is called the Cantle.
It seems strange, but horses do have feathers. There are on the back of the lower leg to absorb water! They are not the type of feathers that a bird would have, but a type of hair.
Stanky Leg Syndrome
The male has an extra leg in between his back two. The females are ridden by both humans and male horses.
some horses get pulled tendons and stuff like that in their legs, if a horse stumbles it can fall and die of a broken leg/neck/back.
A horses toe CAN NOT be located under the hoof, but it can be found on the leg, if you run your hand up the back of your horses leg afew inches up from the hell of the hoof you will find a rather solid bump, that is a toe, although sometimes some have bigger one's then others, it is still considered the horses toe. ;)
A little, its main function is to help pump blood back up the leg.
haunches