Walmart, the nation’s largest grocery retailer, said on Friday that it would ask its meat, seafood, poultry, deli and egg suppliers to adopt animal welfare standards that include sufficient space and easy access to food and water.

The company also said it would ask its suppliers to report to it annually on their use of antibiotics, and asked them to limit treatment with antibiotics to animals that are sick.

The guidelines Walmart issued are voluntary, and the company did not publicly set a deadline for its suppliers to follow its recommendations or say what would happen if a supplier failed to comply. Animal welfare groups, some of which have targeted Walmart’s supply chain in the past, generally applauded Friday’s decision, saying that the company’s market clout would probably compel much of the industry to adopt better standards.

The decision also applied to Sam’s Clubs, the warehouse club unit of Walmart.

“We have listened to our customers, and are asking our suppliers to engage in improved reporting standards and transparency measures regarding the treatment of farm animals,” Kathleen McLaughlin, the senior vice president overseeing Walmart’s sustainability program, said in a news release.