You guys do know that at a certain point, you're just arguing to be arguing, right?
I think the basic nutrition principles that are true for humans are true for most animals: the less processed
the food, the better, no matter what you're feeding yourself or your dogs. Whole foods are just better, period. If I'm not mistaken, the self-regulated dog food industry is relatively young (especially if we are to look at the entire timeline of the evolution and domestication of dogs), and there's no question in my mind that it appeals to the same "values" that, say, the fast food industry does. It's parallel to the generalizations we can make about Americans' diets just by walking through the grocery store and looking at the shelves. We buy it dry, chemically preserved because it's convenient, its shelf-life is way
longer than the individual ingredients would be, we take it home, tear open the bag, scoop out the unidentifiable food source into a bowl and we tell ourselves our dogs are getting everything they need. And it's true, a dog can live a long, disease-free life on even the grocery store-bought kibble. People can survive on a diet of McDonalds and Hoho's and TV dinners and diet soda, too, but it ain't exactly the best for them.
I am fairly certain that whole
grains and various other plant foods do
have nutritional value for dogs, but I bet they'd get more of that value if I, say, take that whole grain brown rice, cook it myself and give it to my dogs than if it's already gone through all of that processing that makes it, mixed with all those other "scientifically devised" ingredients, the kibble that comes out of a bag bearing ANY label. And brown rice is better than white, processed rice. And some grains are better than others. And the fewer chemicals and preservatives the better (and in general, the fewer ingredients
the better). And a cow that eats grass is better for you than a cow that is fed hormones and animal meal (thank you, mad cow disease for that
lesson!). Processing foods, breaking them down for mass production, strips them of a lot of the nutrients they would provide whole. Cooking
food changes its chemical make-up. It really isn't that complicated.