At first it may appear that this frighten German Roller has just messed his feathers up but a closer look in the second photo shows that it is too thin, so thin that the ridge is really a very sharp breast bone!
Too thin birds will not sing in competition nor show them self well at other competitions. It is a waste to take them and with additional weight loss they will likely get ill.
Several things can be done to put weight on a bird. It lots more perches and easy access to food. More oiley seeds such as sunflower chips and more carbs like pieces of bread. I also noticed that birds who ate the most Meatbird formula developed more breasts!
Look at the chest on this well-endowed German Roller Young Cock. Can't wait to hear him sing!! Hope he doesn't mind me calling him Dolly!! (He really loved the Meatbird crumbles!)