Need more info.. is he that close to being finished or are you trying to make weight? If he is close to being finished, using something like Sunglo's Show Cattle Explosion will help. What is your current ration?
He is on a custom feed that we mixed up and getting a pound a half of calf manna a day someone told me to try probiotics and do not let him out at night keep him in all the time and this is just to make weight.