Maybe not. I have no way of knowing. But US beef cattle were being fed chicken poo up until Jan of 2004. Yes. Tasty *Beef ... It's what's for dinner* ... they were all chowing down on poultry litter aka manure, shavings, feathers, dead birds, spilled feed, and whatever else is on the floor of the poultry shed. I know the biologists, nutritionists, and scientists have worked years to get the commercial feed recipe *just right,* but it seems icky to me.
Poultry litter has a calculated value of 50 percent total digestible nutrients (energy). That makes it comparable to average-quality hay, said Rankins, whose Extension work focuses on beef cattle nutrition. Research had proven it was a valuable source of energy for both stocker cattle and brood cows. It was also a good source of protein and essential minerals. Source
http://www.aces.edu/dept/extcomm/newspaper/jan30b04.html
I know. This doesn't prove anything. It's just anecdotal.
When I wrote "leftovers" in animal feed, I was talking about things like outdated bakery goods, outdated chocolate, outdated gum still in the wrappers, poultry by products, the stuff leftover after all the oil has been removed from the soybean. They're looking for ways to feed chickens and pigs the leftovers from biodiesel production. Leftovers. The article above mentions peanut hulls and gin trash. Okay, so they're being smart and not throwing the leftovers into a landfill. And I'm having leftovers for lunch today. So.
Seriously, I'm not saying I haven't or won't ever feed our chickens commercial feed. It obviously is an effective way to feed animals. And it's easier than grinding my own. Much easier.