I guess its a lot like raising show animals. It sounds disgusting, but lower grade base products WILL be seen in the manure. You'll see the consistency and amount change also. We use to put corn in the crockpot ever night to feed the next day to soften it so the animals were able to digest it. You would go from seeing alot in the manure to none. There is so much more than just a feed tag. I have seen two feeds fed to two similar show calves with nearly identical nutritional breakdowns (feed tags). One was a name brand (moormans showtec)...one was made in a feedmill locally. The feedmill feed was made from bulk grains. The breakdowns were the same, digestibility was NOT, the end result was SURE not.