Healthy mammal liver tissue and heart muscle don't have fat in them. Mammal and bird fats tend to be unsaturated fats. In the warm-blooded creature they remain soft, but at cool fish temperatures they harden and go waxy. So, though you may feed some beef heart or liver, muscle meat from any bird or mammal is not recommended as fish food. The essential unsaturated fatty acids that must be supplied in the fishes' diet, are not the same series that warm-blooded creatures require. "Wild Discovery" photographers might throw the carcass of a capybara to the piranhas, but the piranhas' more usual prey are other fish.
Fish aren't geared to deal with much fat and lipids anyway. Surplus fats that can't be burned get stored in the fishes' liver. Eventually the liver tends to enlarge, finally badly enough to make the fish look bloated. Liver disfunction results in retained water, a condition we still might be calling "dropsy" or attributing to constipation.
Though chicken meat wont really be a good thing, following quote from The Skeptical Aquarist:
Healthy mammal liver tissue and heart muscle don't have fat in them. Mammal and bird fats tend to be unsaturated fats. In the warm-blooded creature they remain soft, but at cool fish temperatures they harden and go waxy. So, though you may feed some beef heart or liver, muscle meat from any bird or mammal is not recommended as fish food. The essential unsaturated fatty acids that must be supplied in the fishes' diet, are not the same series that warm-blooded creatures require. "Wild Discovery" photographers might throw the carcass of a capybara to the piranhas, but the piranhas' more usual prey are other fish.
Fish aren't geared to deal with much fat and lipids anyway. Surplus fats that can't be burned get stored in the fishes' liver. Eventually the liver tends to enlarge, finally badly enough to make the fish look bloated. Liver disfunction results in retained water, a condition we still might be calling "dropsy" or attributing to constipation.