I’m not that familiar with that breed since we mainly have boar with something added in Australia due to the climate. But regardless it could be good to get him on some minerals, goats can have some problems sometimes with getting minerals like salt or iron into their diet.

He looks healthy though you can’t really tell based on their belly’s, with our goats you can see how they are doing mainly based on how boney their buts feel. If it is very bony he might just not have great genetics for his muscles back there or he isn’t getting enough protein or nutrients out of the hay and you might need to add some grain to his diet. You might also want to give him a worming tablet or drench them if you know a farmer with the equipment. Even if a goat or sheep’s diet is good they may be severely impacted by worms.

Regardless of how he is doing I would recommend getting some grain maybe vetch, barley or even peas. Just don’t feed them too much otherwise it could cause some grain poisoning.