KFC began offering meatless chicken at one store Tuesday. It sold out almost immediately.

No chickens were harmed in the making of the new KFC nuggets and wings going on the menu in Atlanta.

A single KFC franchise — near the SunTrust Park baseball stadium in Atlanta — on Tuesday began offering meatless chicken from the plant-based food company Beyond Meat. The deal makes KFC the first fast-food restaurant to serve plant-based chicken.

The early results? It sold out almost immediately. Customers posted pictures of hours-long lines as cars and pedestrians wrapped around the building, waiting to order.

KFC announced that the plant-based chicken sold out in less than five hours, and that the store sold as much plant-based chicken in those five frantic hours as their usual popcorn chicken sales for a full week.

It’s a huge step forward for both KFC and Beyond Meat — and for chickens, nearly 50 billion of which are raised in factory farms in the US annually.

“KFC is an iconic part of American culture and a brand that I, like so many consumers, grew up with. To be able to bring Beyond Fried Chicken, in all of its KFC-inspired deliciousness to market, speaks to our collective ability to meet the consumer where they are and accompany them on their journey. My only regret is not being able to see the legendary Colonel himself enjoy this important moment,” said Ethan Brown, the founder and CEO of Beyond Meat, in the press release announcing the deal.

Founded in 2009, Beyond Meat produces plant-based products that imitate the taste, texture, and nutrient profile of meat without killing any animals. Earlier this year, the company went public, and its stock has soared as more and more restaurants sign plant-based meat deals.

Beyond Meat has signed deals with Del Taco, Carl’s Jr., Subway, and the national food distributor Aramark, among restaurants and grocery stores nationwide. Competitor Impossible Foods has teamed up with Qdoba, Burger King, and the national distributor Sodexo, among others.

So far, Beyond Meat, like its competitors, has largely focused on imitation beef, with its signature Beyond Burger and new offerings of imitation ground beef. There are some good reasons for plant-based companies to start with beef: Cows are huge contributors to global warming, and there are big sustainability gains from replacing them with plant-based products.

But there are also some good reasons chicken should be at the top of the agenda. Each cow produces a lot of burgers, which means we kill far more chickens than cows to get the same amount of meat. And chickens are among the worst-treated animals on factory farms, caged in small, chemical-treated spaces where disease is rampant, and engineered to grow so quickly that their legs give out. Chicken farming also contributes to public health problems like antibiotic resistance and the spread of bird flu — and yes, chicken factory farms have a carbon footprint too.

For those reasons, animal welfare researchers have urged plant-based meat companies to figure out a substitute for chicken and other farmed chicken products like eggs. Now, Beyond Meat has answered that call with a partnership with the most famous fast-food chicken restaurant in America.

“Beyond Fried Chicken is available in nuggets with choice of favorite dipping sauce, like KFC’s signature Finger Lickin’ Good sauce, or boneless wings tossed in one of three delicious sauce options: Nashville Hot, Buffalo or Honey BBQ,” KFC announced. If consumers in Atlanta agree that they’re finger-lickin’ good, the meatless nuggets could hit menus elsewhere soon.

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