The Humane Society of the United States on Tuesday applauded Denver-based Quiznos sandwich restaurant chain for announcing that the company will work closely with suppliers to eliminate controversial pig "gestation crates" from its supply chain.

The cages, used to confine breeding pigs, have been criticized in recent years by animal-welfare advocates and the food industry alike, said the Humane Society.

Quiznos will work with its suppliers to eliminate the crates from its supply chain between 2017 and 2022.

Quiznos introduced some gestation-crate-free pork into its restaurants in 2008.

"Quiznos was one of the first chains to begin using gestation-crate-free pork, and we applaud the company for now moving the ball forward for animals even more," Matthew Prescott, director of food policy for the Humane Society, said in a news release.

Elizabeth Sapp, Quiznos' senior vice president of communications, said the company was proud to have been one of the first companies to incorporate gestation-crate-free pork into its supply chain.