Associated Press
Last month, the retailer asked managers across the country to improve their dairy, meat, and produce departments, report Steven Greenhouse and Hiroko Tabuchi at The New York Times.
The memo was in response to customer complaints, the newspaper reports.
In the document, Wal-Mart "tells stores to be sure to 'rotate' dairy products and eggs, which means removing expired items and adding new stock at the bottom and back of display cases."
The New York Times reporters paid a visit to a New York Wal-Mart, where they observed "dented and dirty" milk cartons and a poorly-stocked produce section.
The Wal-Mart manager who provided the memo told the New York Times complained that his store was understaffed.
Bloomberg reports that Wal-Mart's workforce fell by 120,000 people since 2008. In the same time frame, the company added several hundred locations.
The decrease in headcount led Wal-Mart customers to complain of empty shelves at some of the retailer's locations.
Wal-Mart's operations are hurt by "the lack of labor in the stores to get the inventory out of the back rooms and onto the sales floor," Bloomberg's Renee Dudley reported, citing a Cleveland Research Co. note.
The retailer is in the process of expanding its grocery offerings.
Through a partnership with health food brand Wild Oats, Wal-Mart will sell organic groceries that are about 25% cheaper than other products on the market.
Wal-Mart is planning to cut back on store investments and spend more on e-commerce in the face of stagnant same-store sales and falling store traffic in the US.
The company cut guidance for 2015, saying that it expected growth of 2-3% compared with previous estimates of 3-5%.
"There is no excuse for us not to be doing better," Wal-Mart Stores CEO Doug McMillon said during the company's annual meeting with investors last month. "We recognize our situation has changed and we're responding accordingly."
We've reached out to Wal-Mart for comment and will update when we hear more.