It means 1) Backyard chickens should be encouraged because they are less likely to have problems with Salmonella bacteria and 2) basic sanitation is always appropriate in any animal operation.
Why would backyard chickens be less problematic?
First, because they are healthier to begin with. If you've ever seen the pictures of caged layers, your aware that close confinement is not producing healthy birds, then
Second, when disease does break out, it can spread to hundreds or thousands of birds in those confined operation, which can put millions of consumers at risk, so even if all birds were equally healthy to begin with, smaller, distributed flocks would pose less risk, and
Salmonella bacteria survive well in wet environments shielded from sunlight.
Survive well between pH 4 to 8 and temperature between 8∞C and 45∞C
Since salmonella are facultative anaerobic bacteria, they survive well under low oxygen tension, such as that found in manure slurry pits
Salmonella is destroyed by the drying effects of wind, by the bactericidal effect of UV irradiation from the sun, and by disinfectant agents, such as chlorine solutions, iodines, quarternary ammoniums, and phenolics
So birds and coops that have access to sunlight are less likely to support conditions that keep Salmonella viable.
As noted in the second paragraph, merely having backyard chickens is not enough to ensure maximum safety. For best management guidelines on backyard flocks, please see the Center For Disease Control's publication dealing with In-town Flocks.
