In a unanimous decision, the U.S. Supreme Court overturned a California law on Monday that required the euthanization of downer livestock, to promote animal welfare and keep them out of the food supply.

In 2009, California enacted a ban on selling or slaughtering downer, or lame animals unable to walk, in response to undercover footage showing animal handlers abusing cows — forcefully dragging and forklifting non-ambulatory animals — in a San Bernadino County slaughterhouse. The video, released by the Humane Society, sparked consumer outrage and led to the nation’s largest-ever meat recall.

Non-ambulatory cows are at a higher risk for BSE, or mad cow disease. The packer caught prodding downed animals into slaughter had also been supplying the National School Lunch Program.

California’s law required meat processors to remove downed animals — including pigs, goats, and sheep — from the herd and euthanize them immediately. Federal law currently only prevents downer cows from being slaughtered.

The Federal Meat Inspection Act prohibits state regulation that goes above and beyond, or is different from the law, which has ruled over the meat industry since the beginning of the 20th century. The National Meat Association challenged the California’s law, on behalf of pork producers, and a federal judge in Fresno, CA struck down the slaughter ban. The decision was later reversed by the 9th U.S. Circuit of Appeals in San Francisco. The judge called the lower opinion “hogwash.”

In its decision released this week, the Supreme Court noted that the federal meat inspection law “expressly pre-empts” the California law’s application to federally inspected pork facilities.

“The Supreme Court’s ruling affirms the supremacy of the Federal Meat Inspection Act and USDA’s role in regulating meat process plants,” said NPPC President Doug Wolf, a hog farmer from Lancaster, WI. “It also recognized that non-ambulatory hogs with proper recovery time and veterinary oversight do not need to be condemned immediately in all cases.”

Animal rights advocates argue that the California law would promote humane treatment and keep sick, weak animals out of the food supply. According to NMA, around 3 percent of pigs are non-ambulatory, or unable to walk, when they show up to the slaughterhouse.

“Non-ambulatory hogs that are allowed to recover pose no food-safety risk to the public,” Wolf said. “Such pigs are inspected by USDA inspectors and veterinarians regarding their fitness for processing and entering the human food supply, and strong regulatory safeguards for humane treatment in the processing of animals already exist.”