For sure! And if you’re experimenting at home with such ingredients, you can definitely get away with including some of these ingredients in higher amounts, and seeing what happens! If you’re having several hundred thousand company dollars pass through your hands each week in the form of feed formulations though, nutritionists tend to try to be safe rather than sorry. Plus, these are all byproducts and byproducts, while often very cost-efficient, can have a high degree of nutritional variability, even within the same load. Maybe x amount got cooked too much and lost this percent of its nutritional quality and y amount wasn’t cooked long enough and isn’t as bioavailable. That’s why most byproducts are kept at fairly low inclusion levels.I
could link a bunch of studies over the past two decades - started reading up on it when I saw Justin Rhodes' recipe called for it in quantity - its one of the better, if not the best, "make at home" internet chicken feed recipe. But yes, like any other ingredieant, you need to know what you are buying, and when the nutrititional success of your feed mix is heavily reliant on a single ingredient (as it is in J Rhode's case with the Fish Meal inclusion), its that much more important that you know what you are buying.