How safe are free-range eggs?

Years ago – before we moved here and put a dog inside – the shed out back was a chicken coop. These were the original backyard chickens. A resurgence of small-flock rearing has led many to wonder (and make assumptions) about the safety of free-range eggs.

Joel Keehn wrote on Consumer Reports’ Health blog this weekend that,

"About a year ago I took my 11-year-old daughter to the emergency room with what turned out to be salmonella poisoning. My first thought when I heard the diagnosis: Did she pick up the infection from our flock of chickens? But the public-health outreach worker at the local department of health said that was unlikely.

"While eggs are indeed a leading cause of salmonella poisoning, the bacteria that causes the infection may be more likely to breed in the cramped confines of factory farms than in free-range, backyard chicken runs like ours."

Oh? That’s an interesting assumption. And Keehn doesn’t provide anything to support it.

As far as I can tell, salmonella contamination of eggs from various farming methods has not been well-researched…save for one study rumored in January 2008 to have been conducted by the UK government that "showed that 23.4 per cent of farms with caged [egg-laying] hens tested positive for salmonella compared to 4.4 per cent in organic flocks and 6.5 per cent in free-range flocks."

The closest thing I could find was a report by the UK Food Standards Agency in March 2004 of testing results of 4,753 containers of six eggs each (with 16.9% from free-range production systems) that found "no statistically significant difference…between the prevalence of salmonella contamination in samples from different egg production types."

Keehn’s blog post concluded by saying,

"By the way, the health department official who called me up said the most likely source of my daughter’s salmonella poisoning was our pet turtle. That critter is now gone. But I’m picking up four new hens from my neighbor down the road later this week."

I have no reason to believe their eggs will be any safer than those of caged hens. Keehn’s reason is not good enough.