You seem to have your eyes on this and you know what's up. In Minnesota, so far only a few chicken farms have been affected. The egg producer that supplied WalMart in Minnesota destroyed 216,000 birds, and a meat producer destroyed 42,000 birds due to HPAI. These appear to be the only large chicken farms affected. 56 commercial turkey farms were affected and account for the vast majority of the 3 million birds destroyed since May. Why are turkeys so much more vulnerable to infection?
Mostly, I think people are really bad with statistics.
Commercial flocks are tested constantly, so the chances of infection escaping detection are quite low, and the number of affected birds is quite high. That creates the appearance that commercial flocks are the primary source of this, or are somehow particularly vulnerable.
Private flocks are much more likely to not be tested, and when infection is found, the numbers culled are very low - how much of the nation limits backyard flocks to between 4 and 10 birds?
As to why turkeys are seemingly more vulnerable this time around??? It doesn't appear to be a difference in management - large scale turkey ops seem to have moved to climate controlled in-building production much as commercial chicken production did years ago. So its not facilities. It *looks* (though I've not studied closely, I admit) that they maintain similar biosecurity practices and restrictions on employee ownership of personal flocks.
Most likely, I conclude, turkeys are just a little more susceptible to this strain than chickens are, just as ducks and other waterfowl are not as quickly affected and are less likely to succumb to it. But there may be factors I'm not aware of which I've failed to account for - if turkeys are largely raised in cooler climates, and chickens in warmer climates, that would also be a factor - as the ability of HPAI strains to persist in the environment is temperature dependent. It may be there is some market in organic pasture fed "heritage" turkeys raised without those big buildings, and that partially accounts for differences in the numbers of affected flocks...
So honestly, "
I DON'T KNOW", but have some reasonable guesses I'm prepared to defend
until more information changes my views.