There are 3 different types of Horseshoes obtainable from Horses. Each are used to obtain varying amount of Fences that can be used for Breeding.
Horseshoe
Normal Horseshoes are obtained from Tier 1 Horses.
1 Horseshoe = 5 Fences.
Solid Horseshoe
Solid Horseshoes are obtained from Tier 2 Horses.
1 Solid Horseshoe = 200 Fences.
Cemented Horseshoe
Cemented Horseshoes are obtained from Tier 3 Horses.
1 Cemented Horseshoe = 1000 Fences.