Natrona County School District's Food Service Manager says until this past week he was unaware that USDA beef supplied to schools may contain by-product treated with ammonia.

Food Service Manager, Mike Pyska says the beef labeling does not indicate the presence of fillers only the 80/20 fat ratio designation.

Pyska say he's been in contact with purchasers at the state level.

"Next year the USDA is going to offer a choice on whether ground beef has the additive in it and the state is going to opt not to purchase any beef that has the additive in it."

USDA officials maintain the beef filler, treated with ammonia hydroxide, is safe to eat.