Although there is much controversy over feeding birds these products, they are an excellent source of nutrition. The controversy comes from the idea that birds lack the enzymes necessary to digest dairy products. If the products are not fed in excessive amounts, most birds will tolerate them well. Though the feces changes as to what you feed, in this situation the color will be paler green and have a slimy consistency.
The idea of using eggs in the diet should be common sense. We have egg-laying creatures that often exhaust their nutritional supplies by the egg-laying process. What would be more natural than replacing the demand with the product? There is some controversy that this will encourage egg eating, though this argument is largely unfounded.