Fish Food says in response to feather meal in fish food:
"Good fertilizer ... Would you want to eat a fish fed this stuff?"
I'm not convinced that something being eaten by another animal that we find repulsive to eat should be criteria for rejecting eating that animal (or feeding that food). When I was a kid we always ran a few head of hogs behind the cows to eat the corn the cows "passed through". Poultry manure can be fed as part of a balanced feed in a cattle feeding ration. Yet the hogs and cattle tasted fine even though they ate feces. And look at lobster and shrimp. They are the "cockroaches of the sea" (eating goodness knows what off the sea floor) and people lick their chops for them (not me, by the way. My motto is "save a shrimp, kill a cow".
It all depends on amino acids present disgusting or not.
From what I have noticed all part meals are not equal. For example the protein digestibility of internal organs is much better than say chicken feet.
I like "surf and turf"
