Not w/o knowing what dog or cat food is being used - though I can make some guesses.
Corn is your typical feed "filler". Not that its bad, its just not good. It provides ready energy, isn't an excessive source of fat, is low protein, and has a deficient Amino Acid profile in that protein. But its cheap, and its not so deficient that its weaknesses can't be compensated for with reasonable amounts of more [nutritional element]-dense food.
Oats have higher protein than corn, and an AA profile which is better than corn's, though it remains across the board deficient for the four we care about - Methionine, Lysine, Threoning, Tryptophan. Its also high in beta-glucans, which can block some nutrient absorption, and contributes to "sticky poops". Dehulled oats are actually a bit low in fiber, standard oats have about 2x the desired fiber levels in a bird's diet (though there's a pretty broad range of tolerance), and should be balanced with other low fiber ingredients to compensate.
BOSS is an off the shelf, readily available, solution to increasing protein levels when protein is all you care about. Which means, the kind of thing people do when they know just enough to be dangerous. It has the bare minimum in protein levels recommended here in the US (around 16%), and has an AA profile that meets or slightly exceeds the recommended levels of Met, Lys, Thr, Tryp. Sounds great. It also has 3x the desired fiber levels, and 10-12x the desired fat levels. Its a recipe for fatty liver disease and sudden poultry deaths. In my view, its benefits with protein and a good AA profile are MORE than offset by its high fat, and should only be used as a tiny portion of a chicken's diet.
and then we guess about the dog/cat food.... Lets Say we use Purina 1, Grain Free. That's 30% protein, 17% fat, 4% fiber.
The amino acid profile is unknown. It starts pretty low, but the first ingredient in the Purina One is beef, which should help with Methionine, then chicken meal, then canola meal and soy meal - all efforts that should help with Met and Lys both.
That calculates as 16.65% protein (target is 16% min, 18-20% preferred), 9.38% fiber (target is 3.5% +/-, with an acceptable range of about 2.5% - 7%), 18.68% fat. Target is 3.5% +/-, 4.5% for waterfowl like ducks and geese. The only poultry recommended for fat in the 5-6% range is CornishX during "finishing" to bulk them up for table - NOT a feed program intended for the long term health of the bird. Oh and ducks intended for foie gras.
But its the recipe of an internet "expert" demonstrating their ignorance, and hoping desperately that their reliance on a commercial feed prepared for a completely different animal compensates for their educational failings.
Needless to say, i am NOT a fan.
