I halter and tie the horse... feed... then let the horse go again once food is gone. I do not brush or pet while feeding. I do not approach while holding feed bucket. I catch...halter, tie, go get feed bucket, feed.. then when feed is all gone.. approach, untie and unhalter.
No hitting, no yelling. Just show this horse .. "no tie... no food" . If I cannot catch and halter this horse, that is a different training program all together. No hand feeding on food aggressive horses.. Stand near by while horse is tied in case of problems. I have a hay rack and they can eat from both sides and circle. If I push the hay rack up against the fence the food aggressive horse will pin the other. No matter how much hay is in the rack he will defend it. With the ability for him to own a whole side of the hay rack and the ability of the other horse to move out of his way, the fights are gone...
I have two horses. I have tied both during training process. It takes time, it is worth it. They both eat in a designated spot. Now I do not need to halter either, they stand in front of their buckets. They eat and do not compete. If I feel the "feed tude" is returning, we go back to haltering and tied horses.
My problem was with one gelding that would squeal and kick and protect his feed both pellets and hay. Tied for feeding took away his shark attitude, allowed him to relax because this is the rule. It also makes a nice horse to catch because reward for halter and tie is food.
Since he also would attack my other horse when I was approaching with the hay... I walk to my hay storage area, toss a bit on the ground over the fence as I walk by. Piggy boy goes for the tidbit of hay... I then have time to take the bulk of the hay to my hay rack.
This system works very well and has created a very nice happy boy out of the little stinker he used to be... He used to bite at me and the other horses and everything around him prior to this training. He now has an expectant happy face and knows the rules..