Here, I think this is what
@PMD PerformanceHorses might be trying to say. I don't have any
Walmart meats (one of these might be as I'm not sure where it came from), but I took pictures of a few labels on meats from another chain store.
Some of these DO have added ingredients, and those people probably wouldn't be feeding their chickens them anyways. For preservatives, they would say something that would have to do with preservation as previous people have said.
On a lot of stores, the meat is only out there until a certain date, then they are thrown in a freezer and sold in the freezer section. (Sometimes labels/packaging is changed to fix a freezer date instead of fresh date.) That's the preservation on meats with no added ingredients, unless, of course, they went through some preservation process (which might still be on the label somewhere, and is probably only done on meats like sausage, bacon, etc.).
As far as the meats I'm giving my chickens, they're usually from a friend or relative, and if it's deer, it was either given to us or a fresh roadkill (that was safe for human consumption). For meats like hamburg and such, my family will eat freeze it until we're ready to eat it. If it's getting thrown out, it's no longer fit to eat, so my birds never get any of it.
I hope this post clears up some confusion for everyone concerning store bought meats. All in all, check for an ingredient list on your meats before feeding it to your chickens, along with the expiration date. If the meat looks or smells off, despite it not reaching its expiration date, don't feed it to your chickens because it could have spoiled.
