Is oats a good feed for horses?

Oats are a good feed for horses. They are palatable and have a good protein profile. If you feed oats, you will usually need to add minerals as well. Oats, like most hard feed, contain a fair amount of starch, so you should not feed large quantities of hard feed. Base the ration on plenty of forage instead. Most ready-made feeds are a blend of oats, bran, minerals and so on, so the only difference between feeding a ready-made feed and feeding oats is that with oats you mix the ration yourself and top it up with minerals and the like.