How many apples and per day for a freisan horse?

I don't give my horse apples much but, I do when he does something good like he lets me groom him without a fuss and was did good when being ridden. So basically I only give my horse apples as a "good boy treat", I do the same with carrots. But some people give their horses apples twice a day. 2 apples in the morning and 2 in the evening. Hope my answer helped you.