Sorry, not quite sure what the problem is. He was cast in his stall and dropped weight after that? His hoof growth continued?????

Oh he was castrated.....hmmm, I think that you need to look into what you are feeding him and the quality of it.

Thanks for your answer
After being castrated his hoof growth goes back to normal weight, but its growth is very low
And its walls are weak and sometimes painful
This reduction in growth rate occurs when the floor by his hoof pad is closed

When horses been castrated their hormones levels changes like it does to use. Review his food source may have to change it. Give them lots of exercises. As for hooves get a good farrier to trim them every 8 weeks. You may want to consult with a Vet as well to check hormones balance.

Thanks
I have talked with several veterinarians ; by using food products & pedicine we have made hooves' growth good & acceptable , but if these ( food products & pedicine) being cut, the ill will appear once again