Fact check: White striping in chicken caused by fat deposits in muscle, is not a disease in birds

The claim: White striping on chicken breasts indicates how the birds were farmed

What does the white striping on chicken mean?

A post shared to a Facebook page called "Kettle Freaks" claims it indicates how chickens are raised.

"The truth about chicken," proclaims a Sept. 21 post. It features two side-by-side images of chicken breasts. The one on the left has white tissue visible and is labeled with the words "GROWN TOO BIG, TOO FAST." The other image has no visible stripes and is labeled as "PASTURE-RAISED CHICKEN."

The post was shared almost 20,000 times within a week.

One commenter asked, "Is this true?"

It's not.

Experts say, white striping is caused by deposits of fat in the muscle. All the birds in a flock could have a similar size and growth rate, yet some may end up with white striping while others may not. Organic and free-range birds can have white striping as well.

Fact check: No, Impossible Burgers don't contain more estrogen than transgender hormone therapy

USA TODAY reached out to the user for comment.

White striping not linked to mistreatment

Deposits of fat in the muscle happen during the growth and development of the bird, so white striping is a quality factor in chicken breast meat, according to Tom Super, National Chicken Council senior vice president of communications.

Some research has found larger bird sizes can affect the frequency and size of white striping, but researchers aren't sure why, Super said.

However, he said there is no data or research to support the claim that white striping indicates a chicken was treated poorly.

White stripes are sometimes observed in breast meat from meat-type chickens known as "broilers," said Billy Hargis, director of the John Kirkpatrick Skeeles Poultry Health Laboratory at the University of Arkansas.

"This is observed regardless of how these breeds are raised and are more prominent at older ages on some but not all breast filets," said Hargis, who co-authored a study on white striping.

Todd Applegate, head of the Department of Poultry Science at the University of Georgia’s College of Agricultural & Environmental Sciences, also said the white striping is not a direct indicator of how birds were raised – or proof they were raised "too fast," as the post asserts.

Birds have a type of muscle tissue called fast-twitch fibers, which are fibers that don’t have a lot of blood vessels in them, Applegate said. They are meant to act quickly without oxygen.

"The tissue without oxygen, if it grows fast, has to go through a remodeling process, and the process sometimes gets a little uncoordinated," said Applegate, who is a researcher with expertise in poultry nutrition. "What we see there is essentially fatty tissue, but breast meat is very low-fat, to begin with, so typically it adds a minute amount."

A 2016 study in the journal Poultry Science found 96% of the chickens examined had some degree of white striping, though most of those were categorized as moderate. The study found severe white striping can negatively impact meat quality.

Applegate said if you cook chicken with white striping and chicken without it side-by-side, the one with white striping might lose a little more moisture or might not take up as much marinade, but it’s not a significant difference.

"Most people in the public wouldn’t be able to tell the difference, so it’s just inherently how it looks when you go buy it at the grocery store," he said.

The larger birds in a particular flock are often those with white striping. Super said this is an indicator that the chickens aren't suffering or are under any kind of stress that would reduce their food intake and affect their growth rate.

"Birds affected with white striping exhibit good growth performance, livability and health – meaning they are eating and drinking well," Super said.

Hargis agreed.

"White striping is not a clinical disease of chickens and it is associated with healthy individual broilers and it is expected in healthy broiler flocks."

Fact check: Sugar substitute xylitol is dangerous for dogs, found in sugar-free foods

Our rating: False

Based on our research, we rate FALSE the claim that white striping on chicken breasts indicates how the birds are farmed. The striping is caused by fat deposits in the muscle and does not represent a clinical disease in chicken.

Our fact-check sources:

Thank you for supporting our journalism. You can subscribe to our print edition, ad-free app or electronic newspaper replica here.

Our fact check work is supported in part by a grant from Facebook.

This article originally appeared on USA TODAY: Fact check: White fat stripes in chicken show healthy growth rate