Chick-fil-A has ended its 22-year relationship with The Richards Group in a major shakeup at the chicken chain that includes moving its campaign to McCann New York and hiring a roster of agencies for other marketing that will not use its ubiquitious cows.

The changes come a year and a half after longtime Chick-fil-A executive Jon Bridges became the fast-feeder's chief marketing officer. He has been working on a "Cows-plus" marketing strategy, proposing the chain keep using the cows in some marketing while branching out beyond the bovines to tell stories on topics such as food, people and service that might not fit as well into the cow theme.

"The cows are an integral part of the brand. They're our mascot, if you will. But they aren't the brand. The brand is bigger than that," Mr. Bridges said in an interview.

Chick-fil-A's new approach after decades of cows-centric campaigns means The Richards Group is losing a client the agency has had since 1994. The agency introduced the Chick-fil-A cows appearing to paint their famous "Eat Mor Chikin" line on a billboard in 1995. The campaign has helped catapult Chick-fil-A to its perch as the top chicken chain in the U.S., with more than $6 billion in annual systemwide sales.

Mr. Bridges and Joe Saracino, who joined Chick-fil-A this year as VP-brand strategy and media, each commended the work that The Richards Group has done for the chain. The award-winning marketing is best known for its creative use of outdoor advertising featuring 3-D images and messages seemingly written by cows themselves.

"They were such an incredible partner for so long," Mr. Saracino said of The Richards Group.

The advertising helped Chick-fil-A, once a small, regional chicken player focused on mall locations, expand and become the country's 8th-largest U.S. restaurant chain.

"It's not very often that a campaign this successful results in an agency being fired. I don't know that there's much precedence for it," Stan Richards, principal and founder, The Richards Group, said in an interview. "It is a little hard to understand, and in many ways it's the saddest occurrence in my long, professional life."

Instead of having The Richards Group as its main agency for both marketing and media, Chick-fil-A's work will be handled by a roster of shops. McCann New York won the bulk of the business, including cows advertising. Starcom is Chick-fil-A's new media agency. Erich & Kallman, a small, new agency, came up with the first non-cow campaign. DesignStudio was brought on to help with overall brand visual identity and design. Moxie, which has worked on areas such as social media for Chick-fil-A, is also part of the roster as the chain moves forward with "Cows-plus" marketing.

End of a long relationship

Mr. Richards fondly recalled when Chick-fil-A's David Salyers came to the agency's office in 1994, unannounced, to let the team know it won the account.

"He then said, 'I want you to know we will never be your biggest client, but we will do everything we can to be your best client.' And for 20 years, they were. There was no question about that," Mr. Richards said.

Along with the billboards, the cows have appeared in everything from TV commercials to the annual calendars sold by Chick-fil-A and as toys in its kids' meals. The cows even have more than 34,000 followers on Twitter and their own section on the company's website.

"It's been an incredible ride for 20 years," Mr. Richards said. "There are not very many circumstances where you get to do what is recognized as brilliant work and do it consistently for 20 years and never falter. There's not a single piece of work that we put out for Chick-fil-A over those 20 years that I'm sorry we did, that I didn't think was up to our standards. So that hurts when that kind of relationship goes away."

About 30 of The Richards Group's 734 employees work on Chick-fil-A. "It's sad, but it's not catastrophic," Mr. Richards said of losing the account, adding that it is too early to say whether his agency would eliminate any positions as a result of losing the business. "I haven't looked at how much income is going away and how we'll absorb that or how we'll deal with it."

Meanwhile, McCann New York is preparing to work on the cows business and serve as Chick-fil-A's lead agency on brand strategy. Sean Bryan and Tom Murphy, co-chief creative officers at the shop, will oversee all creative.

"This is a great opportunity to work on a beloved and hugely successful brand, and we look forward to bringing fresh thinking and creativity to the business and brand," Chris Macdonald, president, McCann North America, said in a statement.

When asked whether McCann would keep the "Eat Mor Chickin" tagline, he responded that the agency has a "mission to bring that line to life." The agency's first work on Chick-fil-A should begin running sometime early next year, after a handover from The Richards Group. Asked whether anyone from The Richards Group who has worked on Chick-fil-A might move to McCann, Mr. Macdonald said it is "working on building the best possible team."

Chicken for breakfast

Chick-fil-A's sales have increased for 48 consecutive years since the chain began in 1967. The chain keeps growing at a rapid pace despite its decision to remain closed on Sundays for spiritual reasons. Annual systemwide sales topped $1 billion in 2000 and surpassed $6 billion in 2015.

The company is now well ahead of its nearest chicken-focused rival, even with fewer than half the number of locations. Chick-fil-A's systemwide sales jumped 8.8% to $6.29 billion last year, while KFC's U.S. systemwide sales rose 1.8% to $4 billion, according to Technomic. Atlanta-based Chick-fil-A exceeded 2,000 locations earlier this year. KFC had 4,270 locations in 2015, according to Technomic.

Despite its billions of dollars in systemwide sales, and sales per restaurant that exceed those at industry leader McDonald's, Chick-fil-A's marketing budget is modest. The company declined to share marketing spending. According to Kantar Media, Chick-fil-A spent $73.1 million on measured media in 2015, up sharply from $48.4 million in 2014.

"Having the opportunity to partner with Chick-fil-A is truly exciting for Starcom," Kathy Ring, CEO of Starcom USA, said in a statement. "Chick-fil-A is a great brand, and we're looking forward to helping them amplify their message by connecting and building relationships with new and existing customers through our expertise in data and technology."

Under Mr. Bridges, Chick-fil-A has held two jump balls to find creative work that does not feature the cows. The Richards Group participated in each of the sessions, one in 2015 centered on the chain's people, and one in 2016 for a new breakfast campaign. It did not win either project.

Erich & Kallman won the chance to work on the breakfast campaign, which marks the first major TV campaign for the newly-formed agency. Commercials, social videos and other marketing begin airing July 30 and make no references to the cows. Instead, they showcase six historical figures who had what were considered crazy ideas and now have the idea of eating chicken for breakfast. The theme is "Chicken for Breakfast. It's not as crazy as you think."

"The idea chicken for breakfast isn't something that most people pop up in the morning and think about," said Eric Kallman, creative director and co-founder of Erich & Kallman.

The work includes commercials featuring actors portraying prominent people including Amelia Earhart, Alexander Graham Bell, Ludwig van Beethoven, Michelangelo, Susan B. Anthony and Thomas Edison. "Whatever they did historically had to kind of feel like they beat the odds and it was something that people didn't think they might accomplish," Mr. Kallman said.

The spots mix history lessons with current notes. For example, Ms. Earhart is shown flying an old-fashioned airplane resembling one she flew across the Atlantic Ocean, then uses a smartphone to take a selfie.

Steve Erich, co-founder and managing director at Erich & Kallman, said the small agency is set on maintaining a limited full-time staff (for now, it's essentially just him and Mr. Kallman) and reaching out to a variety of partners for projects. On Chick-fil-A, it worked with director Harold Einstein at Dummy Films. Moxie, Chick-fil-A's social media agency, pitched in on extensions of the campaign such as GIFs.

The commercials promote the chain's newest breakfast sandwich, the Egg White Grill, which it began selling on July 18. The introduction of the new, lighter breakfast sandwich comes as Chick-fil-A has seen competitors sharpen their focus on breakfast. Among them, McDonald's continues to see success with its All Day Breakfast menu, after Taco Bell's 2014 breakfast introduction and as chains such as Dunkin' Donuts and Denny's continue to tinker with their breakfast items.

Chick-fil-A began selling the Chicken Biscuit, its first breakfast item, in 1986. However, only 5% of people are aware that Chick-fil-A serves breakfast, Mr. Bridges said. He noted that daily breakfast sales are as low as a few hundred dollars at some locations and up to $10,000 at others.

Now, breakfast is getting its moment in the spotlight. The chicken for breakfast campaign is set to serve as a key part of Chick-fil-A's messaging heading into the fall, a big part of its marketing calendar with its college football tie-ins.