The price of beef has risen dramatically in recent months and years. That's led many consumers to shift away from steaks and towards cheaper hamburgers and meatloaves when they've had a hankering for cow. But record highs mean that even ground beef is getting pricier. What's a supermarket, looking to keep the price of ground beef competitive, to do? Use the cheapest possible kind of ground beef: the much-reviled "pink slime."

According to a recent "ABC World News" report from Jim Avila, 70% of ground beef sold in supermarkets contains the ammonia-treated sludge, which is the the product of a method for salvaging meat scraps from otherwise unusable parts of a carcass.

Avila was tipped off to the startling figure by a whistleblower at the USDA -- who says he has quit his job out of disgust with the product.

The level of usage is consistent with a 2009 report on pink slime by the New York Times. The paper wrote that "a majority" of ground beef in America contained the substance, which is manufactured by a company called Beef Products, Inc.

Since then, fast food companies have discontinued their use of the product en masse. Pink slime is still in the mix of the ground beef used in school lunches, however.

If you want to avoid pink slime altogether, then, and don't want to eat at McDonald's, you may have to buy your own meat grinder. Or stop eating hamburgers.

Watch below for Diane Sawyer on Jim Avila's report: