many livestock feeds would be readily consumed by fish including dog food. But I have learned here that some feeds contain chicken feathers to up the protein count, which is not digestible by fish. Also feeds that are not fish feed may not be highly digestible. I dont know if these feeds would provide more harm than good, but most pay the extra $$ to get the feeds that benefit the fish the most.

It depends on the fish your trying to feed. Catfish may be fine on just about anything. But LMB need high protein content from a fish base source, something with fish meal as the first ingredient.

bodock is right most animal feeds come in medicated and non medicated forms, probably not the best for fish.

Get out and fish.