The decision between caged, cage-free or pasture-raised eggs might seem simple, but it isn't. What's best for the environment may not be best for the bird – or for people
California's egg-laying hens will soon have more room. A state law, which takes effect 1 January, requires egg-laying hens only be confined in ways that allow them to lie down, stand up, fully extend their limbs and turn around freely.
A similar federal bill – which was backed by both the United Egg Producers trade association and animal rights group The Humane Society of the United States, but criticized for not pushing cage-free systems – failed to make it into the 2014 Farm Bill.
While getting more room may be a victory for California chickens, it won't clear up any confusion over what constitutes a sustainable egg.
Read between the lines of a recent study by the Egg Industry Center that touts the emissions reductions in egg production over the past 50 years and you'll find a classic environmental conundrum: what's best for the environment may not be best for the bird. Similarly, what's best for poultry may not be ideal for people.
The report, published in the journal Poultry Science, shows that while egg production has increased since 1960, the industry today releases 71% fewer greenhouse gases. The study's authors point to effective manure management and improved feed efficiency (the ability of hens to convert food into eggs) as the primary drivers of the improvement, both of which are hallmarks of caged egg production systems.
"There are a lot of misconceptions around free-range," says Frank Mitloehner, a professor and air quality expert at the University of California at Davis who studies the impact of animal food products on the environment.
*The case for the cage*
While the general public perception of cage-free or free-range eggs is that they are laid by chickens frolicking in a sunny meadow, the reality is different.
"What is happening in the free-range system is that you have no cages, but there's not a dramatic amount of more space available," Mitloehner says. "You still have barns that the animals are in, so they run around freely but are still in a tight area that is artificially ventilated."
Cages were originally used because they made it easier to extract eggs – the eggs roll down a hill to a collection area, never coming into contact with manure – and also to remove manure, which typically falls through the cage bottom onto a conveyor belt, where it is removed three times a day, Mitloehner says.
The disadvantage of the cage system is that the birds are more cramped, with less space to move, he says. But that lack of space translates to efficiency in the Egg Industry Center report. Because the hens aren't moving, they're not exerting energy on much other than producing eggs.
*Complexities of 'cage-free'*
Meanwhile, the disadvantage of the cage-free system is that manure stays in the barn and can build up, Mitloehner says.
"Animals have a natural drive to work their way through manure to find worms, insects and so on, and they do eat manure as well," he said. "So that's a big problem with respect to food safety and animal safety because animals in that system are now in contact with their manure. If one bird has salmonella, all of the other birds get sick too. Also, anywhere from 10% to 20% of the eggs are soiled because they're laid on that dirt floor."
From a health perspective, Mitloehner says, cage-free systems also pose the greater risk to people working in egg production.
"I'm looking primarily at air pollutants and I've found that in those systems with manure inside that is not being taken out frequently, manure that builds up causes large amounts of dust particles and those particles contain pathogens and toxins that people and animals then inhale."
Cage-free systems in which barns house tens of thousands of hens together also can raise stress for chickens, which naturally collect in flocks of about a dozen. It's similar to putting a cow in a concentrated animal farming operation, in which many cattle are packed into a tight space.
"They cannot establish a pecking order the way they would in a normal-size flock, but it's an instinct so the animal still tries to do this, and that results in a high incidence of cannibalism in cage-free systems, as well as higher incidence of bone breakage," Mitloehner says.
*What about pasture-raised chickens?*
To address both air quality and animal safety concerns, some experts tout pasture-raised chickens – and eggs – as the way to go. The idea, adopted by some organic farms, is a model in which various animals – such as cattle and chickens, for example – rotate through the same piece of land.
"For the overall benefit of land, chickens and people, we should look to systems of pastured poultry where egg production is part of a greater system of food production," says Douglas R. Fox, professor and director of the Center for Sustainability and Global Change at Unity College in Unity, Maine. "I have seen several 'high tunnel' systems [systems in which chickens graze on pasture while enclosed in large tunnels similar to greenhouses] where chickens graze throughout the winter."
According to Mitloehner, however, such examples are few and far between. "It's an absolutely miniscule percentage of the operations in both the US and Europe," he says.
The reason is two-fold: First, the hens themselves don't necessarily want to be in an open pasture. "You'd be surprised how few will venture out onto pasture if they have access," Mitloehner says.
Second, ranchers don't want them out in a pasture, where they're open to attacks from birds of prey and coyotes, as well as diseases carried by wild birds. There's also no way to control manure in an open pasture, Mitloehner notes.
"The bottom line is that these systems can be improved, but it's not as easy as just saying let's put animals on pasture," he says. "From a food safety and environmental standpoint, pasture raising is not great."
Nonetheless, it may be worth working to address the challenges of pasture raising. In addition to the feel-good benefits of thinking about egg-producing hens clucking about a meadow rather than cooped up in either a barn or a cage, a 2010 study from Pennsylvania State University found that eggs from pasture-raised hens could also be healthier – with twice as much vitamin E, brain-boosting long-chain omega-3 acids and total omega-3 fatty acids.
Amy Westervelt is an Oakland, California-based freelance reporter who covers the environment, business and health Reported by guardian.co.uk 7 hours ago.
California's egg-laying hens will soon have more room. A state law, which takes effect 1 January, requires egg-laying hens only be confined in ways that allow them to lie down, stand up, fully extend their limbs and turn around freely.
A similar federal bill – which was backed by both the United Egg Producers trade association and animal rights group The Humane Society of the United States, but criticized for not pushing cage-free systems – failed to make it into the 2014 Farm Bill.
While getting more room may be a victory for California chickens, it won't clear up any confusion over what constitutes a sustainable egg.
Read between the lines of a recent study by the Egg Industry Center that touts the emissions reductions in egg production over the past 50 years and you'll find a classic environmental conundrum: what's best for the environment may not be best for the bird. Similarly, what's best for poultry may not be ideal for people.
The report, published in the journal Poultry Science, shows that while egg production has increased since 1960, the industry today releases 71% fewer greenhouse gases. The study's authors point to effective manure management and improved feed efficiency (the ability of hens to convert food into eggs) as the primary drivers of the improvement, both of which are hallmarks of caged egg production systems.
"There are a lot of misconceptions around free-range," says Frank Mitloehner, a professor and air quality expert at the University of California at Davis who studies the impact of animal food products on the environment.
*The case for the cage*
While the general public perception of cage-free or free-range eggs is that they are laid by chickens frolicking in a sunny meadow, the reality is different.
"What is happening in the free-range system is that you have no cages, but there's not a dramatic amount of more space available," Mitloehner says. "You still have barns that the animals are in, so they run around freely but are still in a tight area that is artificially ventilated."
Cages were originally used because they made it easier to extract eggs – the eggs roll down a hill to a collection area, never coming into contact with manure – and also to remove manure, which typically falls through the cage bottom onto a conveyor belt, where it is removed three times a day, Mitloehner says.
The disadvantage of the cage system is that the birds are more cramped, with less space to move, he says. But that lack of space translates to efficiency in the Egg Industry Center report. Because the hens aren't moving, they're not exerting energy on much other than producing eggs.
*Complexities of 'cage-free'*
Meanwhile, the disadvantage of the cage-free system is that manure stays in the barn and can build up, Mitloehner says.
"Animals have a natural drive to work their way through manure to find worms, insects and so on, and they do eat manure as well," he said. "So that's a big problem with respect to food safety and animal safety because animals in that system are now in contact with their manure. If one bird has salmonella, all of the other birds get sick too. Also, anywhere from 10% to 20% of the eggs are soiled because they're laid on that dirt floor."
From a health perspective, Mitloehner says, cage-free systems also pose the greater risk to people working in egg production.
"I'm looking primarily at air pollutants and I've found that in those systems with manure inside that is not being taken out frequently, manure that builds up causes large amounts of dust particles and those particles contain pathogens and toxins that people and animals then inhale."
Cage-free systems in which barns house tens of thousands of hens together also can raise stress for chickens, which naturally collect in flocks of about a dozen. It's similar to putting a cow in a concentrated animal farming operation, in which many cattle are packed into a tight space.
"They cannot establish a pecking order the way they would in a normal-size flock, but it's an instinct so the animal still tries to do this, and that results in a high incidence of cannibalism in cage-free systems, as well as higher incidence of bone breakage," Mitloehner says.
*What about pasture-raised chickens?*
To address both air quality and animal safety concerns, some experts tout pasture-raised chickens – and eggs – as the way to go. The idea, adopted by some organic farms, is a model in which various animals – such as cattle and chickens, for example – rotate through the same piece of land.
"For the overall benefit of land, chickens and people, we should look to systems of pastured poultry where egg production is part of a greater system of food production," says Douglas R. Fox, professor and director of the Center for Sustainability and Global Change at Unity College in Unity, Maine. "I have seen several 'high tunnel' systems [systems in which chickens graze on pasture while enclosed in large tunnels similar to greenhouses] where chickens graze throughout the winter."
According to Mitloehner, however, such examples are few and far between. "It's an absolutely miniscule percentage of the operations in both the US and Europe," he says.
The reason is two-fold: First, the hens themselves don't necessarily want to be in an open pasture. "You'd be surprised how few will venture out onto pasture if they have access," Mitloehner says.
Second, ranchers don't want them out in a pasture, where they're open to attacks from birds of prey and coyotes, as well as diseases carried by wild birds. There's also no way to control manure in an open pasture, Mitloehner notes.
"The bottom line is that these systems can be improved, but it's not as easy as just saying let's put animals on pasture," he says. "From a food safety and environmental standpoint, pasture raising is not great."
Nonetheless, it may be worth working to address the challenges of pasture raising. In addition to the feel-good benefits of thinking about egg-producing hens clucking about a meadow rather than cooped up in either a barn or a cage, a 2010 study from Pennsylvania State University found that eggs from pasture-raised hens could also be healthier – with twice as much vitamin E, brain-boosting long-chain omega-3 acids and total omega-3 fatty acids.
Amy Westervelt is an Oakland, California-based freelance reporter who covers the environment, business and health Reported by guardian.co.uk 7 hours ago.