First you don’t force feed an animal that knows how to it.

Second he is an 05 and he more than likely has breeding on his mind, sexually mature individuals will go off feed at this time of the year.

At that age and with a good bodyweight he can go months without eating, I know this is frustrating however it does happen you just need to be patient, your animal will be fine.

He was eating before he will eat again in the meantime make sure your husbandry is on spot.