FarmVille has plans for a FarmVille Horse Hall in the works. The Horse hall is a harvestable laboratory type building that can be harvested for Horseshoes. You can then use Horseshoes to unlock new mystery Horses.
For a sneak peek of some possible Horse Hall Horses that you can check out on our FarmVille Freak unreleased post, click here.
The Horse Hall Stages are shown below along with the completed Horse Hall.
FarmVille Horse Hall Stages:
FarmVille Horse Hall Stage 1
FarmVille Horse Hall Stage 2
FarmVille Horse Hall Complete
Here's a look at the Horse Hall's required construction materials. You will need to collect the following parts: Fancy Hay, Pretty Saddle, and Hightech Salt Lick.