My guineas get Kalmbalch Layer pellets with crushed egg shells or oyster shell for calcium for egg making. I will give protein count once my house is up, if I go to the kitchen where we store the food my Doberman pup will start yelping even though she was just outside.
I would drastically...
Maybe try a different food for him with higher protein, offer extra fluids with ACV, Honey Vitamins and Pedialyte mixed in.
I would bring him in keep careful watch if he isn't liking being in the house place him in a crate in the barn or shed so his mate can see and hear him.