Do free-range eggs have more salmonella than regular supermarket eggs?

I've heard that free range chickens have less salmonella. Supposedly because a chicken with a better diet and less stress than battery raised chickens ...which are shoved in teeny little cages and have their beaks lopped off in order to reduce pecking injuries...but I digress...

er, where was I? Ah yes...less stress. Anyway, these free range chicken's eggs will have less chance of salmonella because the natural defences of the egg, that protects environment for a chick, will be intact and strong. Not to mention cleaner. Much of the salmonella problem with eggs in general has come from contamination of the egg shell, or from breaks in the shell itself. At least according to the CDC.

Supposedly.

But as for sources on studies, I've yet to find any specifically done on free range vs. battery raised hens.

No, I would guess that they have less, actually.