Move to outlaw the keeping of hens in small wire cages splits California, with farmers saying it could put them out of business.
WHAT do hens want – and how do humans know?
That's the issue at the heart of a fierce battle looming in California between animal rights campaigners and egg producers over the welfare of caged hens. The outcome could crack the state's $300 million (200 million) egg production industry.
A vote in November on whether to give more space to breeding pigs and calves raised for veal could also make California the first US state to ban the housing of egg-laying hens in small wire cages.
If the law is passed – and support for it is running at 63 per cent, according to a poll – most of California's egg producers would be driven out of business, opponents say.
Proposition 2 would give the state's 20 million laying hens, most of which have less floor space than an A4-size piece of paper, enough room in which to spread their wings, lie down, stand up and turn round.
If approved, the measure will come into force in 2015.
Jennifer Fearing, campaign manager for Yes on Prop 2, said: "California voters recognise this is a modest reform and that all animals, including those raised for food, deserve humane treatment. Californians have a long history of very progressive attitudes towards animals and have a commitment to outlawing animal cruelty where it exists."
In San Diego County, brothers Ryan and Alan Armstrong are proud of their 60-year-old family egg farm business and say it is in their best business interests to provide good conditions for their 500,000 hens.
"If the hens are uncomfortable, if they are too hot or too cold, or don't get enough water or don't like their feed, the first thing that gets hit is egg production," Ryan Armstrong said.
About 10 per cent of the Armstrong hens are uncaged. In one vast, breezy barn, 8,800 brown, clucking hens roam under a 9,000sq foot roof. But the brothers say relative freedom is not necessarily a good thing.
"People have the idea that cage-free is healthier, but it's not. The hens sometimes lay eggs in the manure. Sometimes they eat it. If one is sick, it's impossible to catch and remove it. Another problem with so many hens living together is cannibalism," Ryan said.
Demand in California for cage-free eggs, which normally carry a premium of about $1 per dozen, has levelled off in the past three years, the brothers say.
"We had planned 12 cage-free buildings. but we only put up six because demand is not there," Alan Armstrong said.
They said their highest production came from the sort of conditions that most anger animal campaigners: a computer-controlled, air-conditioned barn housing 130,000 hens, six to a wire cage and with the cages stacked five high.
Manure is collected on trays under each cage; clean white eggs roll on to conveyor belts, and sick or injured hens can be quickly removed. "The supporters of Prop 2 are asking us to throw all that away so chickens can spread their wings, but that doesn't make birds healthier," Ryan said. "Sometimes what is better for a hen isn't what you think it might be."
He said the costs of extra equipment, labour and land needed to meet the Prop 2 changes would "put our family out of business".
Animal rights groups say farms like the Armstrongs' are the exception, not the rule and that the Yes campaign has wide support from animal lovers.
"People get it," Ms Fearing said. "We would never keep our pets in cages so small they couldn't turn around, and farm animals don't deserve that misery either."
Europe plans to act in four years' time
THE European Union will bring its ban on keeping laying hens in tiny cages into effect in 2012 – from that date it will allow only "enriched" cages, which offer a bit more room.
An estimated 200 million hens in the 27 EU countries are kept in cages.
Official figures show that 62 per cent of Britain's 29 million laying hens are kept in battery cages, while a third are free-range and 4 per cent are kept in barns.
In California, exposs of poor animal welfare standards have played a major part in shaping public opinion on battery farms, much as they have in Britain.
An undercover investigation in May by the vegan campaign group Mercy for Animals of a large egg farm in Merced, northern California, showed video of rotting hen carcases in cages with live hens and scrawny hens covered in excrement.
And as with many other examples of legislation in the United States, such as on environmental issues, where California leads, other states are likely to follow.