Oregon, Colorado, Maine, Michigan, and Ohio banned at least
one of these systems through legislation.
Consider the wording of California's Prop 2, which reads
A person shall not tether or confine any covered ani-
mal, on a farm, for all or the majority of any day, in a
manner that prevents such animals from (a) lying down,
standing up, and fully extending his or her limbs; and
(b) turning around freely.
—Proposition 2, State of California, 2008, accessed
November 25, 2013, at http://ag.ca.gov/cms_pdfs/
At the time it was passed, many farmers were not sure how
to comply with the proposition since specifics on acceptable
housing methods were not established by the proposition
nor the Humane Society of the United States (HSUS). Notice
the proposition does not ban cages. Are cage-free production
methods the only acceptable methods? What about caged
systems (such as enriched colony cages) where birds are able
to lie down, stand up, extend their limbs, and turn around?
This was not what the HSUS had in mind, though, and the
disagreement led to a lawsuit by the Association of California
Egg Farmers (and others) requesting clarification about exactly
what Prop 2 means in regard to acceptable housing systems.
There was also the possibility that California might continue
to import eggs from caged systems in other states (as it had
regularly imported eggs prior to the passing of Prop 2), but
that was prohibited by later legislation.
HSUS and animal scientists in the United States never
agreed about cage-free egg systems. Although HSUS believed
it to be the most humane method of egg production, animal
scientists could only agree that cage-free systems allowed
greater movement and natural behaviors at the expense of