The Australian Egg Corporation Limited has responded to New Zealand's announced shift to furnished or enriched colony cages for its hens, saying that if there was good evidence that hen welfare was significantly improved in colony cage systems, Australia would already have made changes, and that the jury is still out as to whether such colony cages and furnishings in the cage improve welfare for laying hens.

"The Coalition for Sustainable Egg Supply in the U.S. is currently conducting major research comparing conventional with colony cage systems, and the AECL is monitoring the results closely," said the corporation. Australia has a number of colony cage systems, and the corporation continues to invest in animal welfare improvements for all farming systems, including cage-type systems. 

"Not all consumers have concerns about cage eggs, as the vast majority of eggs sold in Australia are cage eggs — just under 70 percent," said the corporation. "Recent research by the University of Sydney suggests there is no difference in the stress levels of hens in barn, cage and free-range farming systems."

There are welfare advantages and disadvantages in each of the three farming systems. The advantages of cage farms are that hens are protected from inclement weather; protected from predators such as foxes, snakes and eagles; have access to clean food and fresh water; are better protected from potentially dangerous diseases such as avian influenza; are protected from soil or manure-borne diseases; and are less prone to bullying by other hens. The disadvantages are the hens have less room to move and display their full repertoire of natural behavior, said the corporation.