A group representing Canada's major grocers has committed to buying cage-free eggs by the end of 2025.

The Retail Council of Canada issued a release Friday saying the voluntary commitment would be contingent on "availability of supply within the domestic market."

The Retail Council includes Loblaw Co. Ltd., Metro Inc. Sobeys Inc. and Wal-Mart Canada Corp., which together represent 90 per cent of grocery retail in Canada.

The commitment to raising egg-laying hens in a humane manner is a further escalation in a movement that has been gathering speed for the past two years.

Restaurateurs such as McDonald's, Tim Hortons and Burger King have already committed to cage-free eggs by 2025. A&W has said it wants cage-free, antibiotic free eggs by 2017.

 All of this is putting pressure on Canada's more than 1,000 egg farmers, who work in a supply-managed market.

Big transition for farmers

Currently about 90 per cent of Canadian egg production is in what the industry calls "conventional housing" meaning cages.

In February, industry association Egg Farmers of Canada committed to a "systematic, market-oriented transition from conventional egg production toward other methods of production for supplying eggs."

Egg Farmers of Canada declined an invitation for an interview with CBC on the transition, but posted a statement on its website saying it remained committed to meeting market demand for cage-free eggs.

"We look forward to working with retailers to ensure high quality Canadian eggs remain on grocery shelves everywhere and we will continue to work with our supply chain to do so and to align our approaches as much as possible," the statement said.

The farm group also warned of some of the trade-offs in the transition, including worker health and safety and food affordability.

In February, the group said it might have achieved change to half of the existing conventional housing within eight years, with battery cages gone by 2036. The grocers' commitment will likely push producers to move more quickly.

The Retail Council said it has been in discussions in recent months with producers, processors, the scientific community and consumers regarding the best approach for raising hens.

David Wilkes, vice-president of the grocery division of the Retail Council, also warned of restrictions as a result of Canada's supply management system, which might prohibit importing of cage-free eggs from elsewhere.

Enriched housing or free-run?

Since egg farmers will have to make significant investments in creating more humane conditions for hens, the farm group said it is most interested in a move to what it calls enriched housing, which allows hens more natural behaviour, including perching, scratching, foraging and nesting.

This is not the same as free-run conditions, which animal rights groups and some consumers have said they prefer.

The National Farm Animal Care Council, which works with both retailers and producers to develop guidelines for raising animals, is currently finalizing recommendations on a code of practice for layer hens.

Sayara Thurston, campaign manager (farm animals) for Humane Society International/Canada, welcomed the announcement by the Retail Council.

"The overwhelming demand for cage-free eggs from the largest purchasers in the country sends an irrefutable message to egg producers that cage systems are no longer welcome in Canadian supply chains," Thurston said.

"This decision will impact tens of millions of laying hens and spells the end of the practice of confining chickens in cages for their entire lives."