No, it is best to put him on a diet of grain and hay.
No, bread is high in starch. The starch can cause fermentation in the cecum and colon. Starch fermentation causes a buildup of lactic-acid producing bacteria in the hindgut and a subsequent drop in pH. The results can range from inefficient feed conversion (weight loss) to colic.
Bread is not good for them
Bread is just sugar. He needs to be on a grain/grass/hay diet