We've implemented a small update recently that includes two things:
New Horses in the Market: There are some good ones, so be sure to check them out!
Purebred stats: Breeding matters in more ways than one! Stats can be important for competitions but now when you breed purebred foals they will receive a boost in stat numbers +100 (20 in each skill). This doesn't only apply to newborn foals, it will also apply to existing horses that are purebred. We'll be sure to get their stats updated for you soon!