Hello breeding a horse is quite simple.
1. Your horse must be 2 and a half years old (Which is sexual maturity)
2. If your Horse is a Stallion you will not be getting a horse you will just supply the sperm. And get paid lol, But incase your hosre is a mare you will get a baby but a baby cost some Equus (money) 50Equus for a scan, up to 600 for a doctor bill and if you dont have enough Equus a fine will come+ Flu shot and Worms Treatment.
3.When your house reaches the age of sexual maturity another box will appear at the bottom right titled REPRODUCTION under it, it will say click it.
4.Next and last step finding the perfect stallion. Each stallion will be a different price 200 to who knows, im sure i dont but you wanna find a stallion with good skills and does'nt cost more than it should and has a good blup level (100) because it helps your foals trait in skills.
Hopeit Helped if you want Add me Colorlover, i madefor a stallion,Colorlover2008 for a mare.lol....Add my friend Lucky2448 she wishes to breed with a mare.......because i thought tou can only have 1 horse lol......