Notice has been filed of a planned appeal by several egg-producing states outside California objecting to the requirement that only eggs from hens kept in so-called Proposition 2 cages can be sold in California. A trial judge earlier rejected the claims on grounds the states representing their egg producers lacked standing to bring the case. Most U.S. egg producers use battery cages, which California voters in 2008 said had to be phased out in that state based on concerns about how much space hens should have to stand up and turn around. When it became apparent that the California requirement would put its egg producers at an unfair disadvantage, state lawmakers extended Proposition 2 requirements to all producers selling eggs in California. It all goes into effect on Jan. 1st, a date that will likely see egg markets disrupted with possible price increases in California. States filing notice of appeal — Alabama, Missouri, Nebraska, Oklahoma, Iowa, and Kentucky — argue California is imposing an unfair and unconstitutional trade restriction on out-of-state eggs. California’s new dictates for cage sizes have so far had little impact on how U.S. egg producers house their hens — about 95 percent still use their battery cage systems. It’s unclear how many egg producers in California have switched to Prop 2 cages. Battery cage infrastructure not only provides housing for the hens, but also are complex systems for feeding and watering, waste disposal, and collecting the eggs. Egg producers say battery cages help prevent disease and turn out cleaner eggs. Changing out all battery cages in the U.S. might cost as much as $10 billion. Attempts to set a national standard for laying hen cages failed both as standalone bills and as an inclusion to the 2014 Farm Bill. Three other states — Michigan, Oregon, and Washington State — have adopted their own cage requirements, but only California is attempting to restrict trade from other states and foreign countries based on the issue.