This attraction does pretty much what it says on the tin. There are fields of horses, and you can buy bags of food in the shop to feed them with.
It's not going to occupy a whole day, but it's certainly worth popping in, spending a pound on a large bag of food, and then going and meeting the horses.
There's a little cafe, a shop with a decent range of (most horse themed) stuff.
Definitely worth a visit!