The move comes four months after a video showing disturbing images at a Manitoba pig farm was made public.

Joining other members of the fast-food and retail sector, eight Canadian grocery chains say by 2022 they will stop buying pork from producers that use gestation stalls, metal crates where pregnant sows are kept until they give birth.

The Retail Council of Canada, which represents Canadian grocery stores, says the move will come gradually to give pork producers time to make the changes, which require “significant financial investment.”

The grocery companies that made the pledge this week include Costco, Loblaw, Metro, Sobeys and Walmart.

The companies will work with the National Farm Animal Care Council and Canadian Pork Council, which is updating pig codes of practice to deal with several issues related to animal welfare, the RCC said. A draft code is expected to be published in June.

The announcement was welcomed by animal-welfare groups, including Mercy for Animals Canada, whose volunteer investigator worked undercover at the Manitoba pig farm last year and filmed images of employees swinging a piglet into a metal post to euthanize it, pulling on pigs’ ears and kicking animals.

“We are pleased that retailers have finally listened to their ethically-minded customers and are taking action to end the abusive practice of confining pigs in tiny metal crates so small the animals cannot even turn around, walk or lie down comfortably for nearly their entire lives,” Twyla Francois, Mercy for Animals’ director of investigations, said in a statement.

Other companies, including Tim Hortons and McDonald’s, have policies requiring their suppliers to phase out the use of gestation crates.