General Mills is working toward using only cage-free eggs in its products, joining several other large food manufacturers and retailers.

Golden Valley-based General Mills' cage-free egg goals were announced Wednesday, part of an update of animal welfare policies for its supply chain. The company is a big egg user in its baking products, including Betty Crocker cake mixes and Pillsbury refrigerated dough products.

General Mills, maker of everything from cereal to soup, said it supports "five freedoms" for all animals in its supply chain: freedom from hunger, discomfort, fear and pain, as well as freedom to engage in "normal patterns of animal behavior." Previously, General Mills had applied the five principles only to dairy suppliers.

"Certainly the highlight of this announcement is the commitment to switch to 100 percent cage-free eggs," Wayne Pacelle, head of the Humane Society of the United States, wrote in a blog post. The Humane Society has worked with General Mills on its animal welfare policies, as it has with other large companies.

The common arrangement in the U.S. egg industry is to pack several hens in small cages, giving them little room to move. In cage-free housing, hens are still kept indoors, but they have room to walk about and flap their wings. Animal rights groups have long decried the cage system.

Cage-free eggs come at a premium price and the cage-free segment of the egg business is still relatively small. But it's growing as some consumers have increasingly embraced animal welfare issues.

Kellogg, Nestlé, Starbucks, Wal-Mart, Sodexo and Aramark — the last two both large institutional food providers — have all made public pledges to move away from the cage system in their egg supply chains. Some companies have put timelines on their cage-free goals, looking to make a total switch-over by 2019 or 2020.

General Mills has set no dates for its cage-free initiative. "We didn't feel comfortable committing to something that we just don't have a clear line of sight on at this time," said Steve Peterson, director of sustainable sourcing at ­General Mills.

Even with supplier pressure, the egg industry could take years to convert to cage-free, given the expense.

Potentially making things more difficult, the Upper Midwest's egg industry is currently in turmoil after avian flu wiped out more than 30 million birds this spring. While General Mills had been working on a cage-free policy "long before" the bird flu touched down, Peterson said, the outbreak has slowed the initiative down a bit.

"We've been careful with our strategic suppliers," he said. "We didn't want to exacerbate the situation."

In the dairy business, General Mills said it's working along with other companies and farmers associations to "understand the issues of pain relief" for dairy cows, including "dehorning" and "tail docking." The company said it supports breeding programs to develop naturally hornless cattle, an approach that has worked in the beef industry.

General Mills relies ­heavily on milk for its big Yoplait yogurt business.