Pond Boss Forums MANAGING AN EXISTING POND Feeding Fish Food Primer

That is not really my point. But your explanation does create more questions.

I will use protein as an example. Original point was - Is not all injested then digested protein broken down into the basic amino acids and then those basic amino acids reassembled as new protein into the new organism; all controlled by that organism's physiological processes (ultimately DNA?)?

You new comment created this question - what makes a protein undigestable? Is it a coating on that protein or inability of the consumer's digestive fluids to separate the protein into the basic amino acids?

Hair is evidently not digestible by cats which is why they cough up hair balls??? However some organisms can apparently digest hair such as birds of prey and maybe bass or foxes who eat mice? Birds and some predators can digest bird feathers but fish can't normally digest feathers until the feathers are first processed???