If I was you I would feed him on schedule, if your intent are to breed him feed him while he is eating because he will (most likely) stop eating soon enough, and since breeding can take it's toll, your male could lose a significant amount of weight during breeding season. (you do not want to have to pull him out of rotation because he is too skinny do you?)
While you want breeding male to be on the athletic side you do not want to starve them either.