Let's talk turkey - why were they impacted first in large MN farms?

[Emily]

http://agfax.com/2015/04/10/turkey-f...flu-spreading/

April 10, 2015
Turkey Farming: H5N2 Bird Flu Spreading
By Chris Clayton, DTN Ag Policy Editor
Studies by USDA?s Agricultural Research Service have shown turkeys are far more susceptible to the influenza than chickens. Thus, large turkey production areas are becoming hotbeds for the virus.
...
Most of the birds were indoors, but heating or ventilation and airflow all could have led to the spread of the influenza. Water fowl may not get in, but feces from wild birds could. Producers are taking increased biosecurity measures to avoid limiting exposure.

Chickens would have the same risk factors, so why are turkeys so vulnerable? Obesity was a risk factor for pH1N1 in humans, so did selective breeding for heavy breasts make turkeys more susceptible?

http://www.npr.org/blogs/thesalt/201...nts-of-our-big

Can Breeders Cure What Ails Our Breast-Heavy Turkeys?
November 27, 2014 7:03 AM ET

But turkeys are muscle-heavy, not fat-heavy, (and chickens have been bred to be abnormally muscular in the breast, too.) Could a muscle growth-promoting drug that is FDA approved for use in turkeys but not in chickens be the risk factor?

http://foodbabe.com/2014/11/06/this-...holiday-feast/

This Drug Has Sickened Thousands of Animals ? Will It Be At Your Holiday Feast?

http://www.drugs.com/pro/topmax.html

Topmax? 9
ELANCO* AF0621

For Use in the Manufacture of Medicated Turkey Feed.Topmax? 9 Ractopamine Hydrochloride

Pharmacologically, Ractopamine is a beta-adrenergic agonist, or 'β-blocker.' [ETA: See next post - not a beta-blocker.]

http://www.pnas.org/content/106/13/5300.full

Biological Sciences - Immunology:
Kristie M. Grebe, Heather D. Hickman, Kari R. Irvine, Kazuyo Takeda, Jack R. Bennink, and Jonathan W. Yewdell

Sympathetic nervous system control of anti-influenza CD8+ T cell responses
PNAS 2009 106 (13) 5300-5305; published ahead of print March 13, 2009, doi:10.1073/pnas.0808851106

Abstract

Despite the longstanding appreciation of communication between the nervous and the immune systems, the nature and significance of these interactions to immunity remain enigmatic. Here, we show that 6-hydroxydopamine-mediated ablation of the mouse peripheral sympathetic nervous system increases primary CD8+ T cell responses to viral and cellular antigens presented by direct priming or cross-priming. The sympathetic nervous system also suppresses antiviral CD4+ T cell responses, but this is not required for suppressing CD8+ T cell responses. Adoptive transfer experiments indicate that enhanced CD8+ responses do not result from permanent alterations in CD8+ T cell function in sympathectomized mice. Rather, additional findings suggest that the sympathetic nervous system tempers the capacity of antigen-presenting cells to activate na?ve CD8+ T cells. We also show that antiviral CD8+ T cell responses are enhanced by administration of a β2 (but not β1 or α) adrenergic antagonist. These findings demonstrate a critical role for the sympathetic nervous system in limiting CD8+ T cell responses and indicate that CD8+ T cell responses may be altered in patients using β-blockers, one of the most widely prescribed classes of drugs.

Maybe this latest rendition of a deadly avian flu is actually an animal husbandry issue.

 

[Emily]

I think I have this wrong at least as far as mammals go:

Pharmacologically, Ractopamine is a beta-adrenergic agonist, or 'β-blocker.'

Beta-adrenergic agonists are probably the opposite of beta-blockers in mammals, but it could be different in turkeys:

http://molpharm.aspetjournals.org/content/17/1/1.short

[h=1]A Comparison of the Beta-Adrenergic Receptor of the Turkey Erythrocyte with Mammalian Beta[SUB]1[/SUB] and Beta[SUB]2[/SUB] Receptors[/h]

So Ractopamine could still be an issue for flu in turkeys. But if not, it could still be an issue as far as secondary bacterial infections:

http://respiratory-research.com/content/7/1/57 [h=1]Inhalation of β2 agonists impairs the clearance of nontypable Haemophilus influenzae from the murine respiratory tract[/h]

 

[Emily]

Here's another potential risk factor that could explain why farmed turkeys are so susceptible to influenza:

Modern Turkey Industry
The modern turkey industry has developed a hybrid white turkey that is larger and faster growing than purebred or wild turkeys. The modern hybrid turkeys are so large they can no longer naturally breed efficiently. All modern turkeys are artificial insemination...

http://extension.psu.edu/animals/po...l-material/the-chicken/modern-turkey-industry​

In the Turkey Breeding Factory

By Frank Observer A friend heard an advertisement on the local radio about the Butterball Turkey Company needing workers in artificial insemination, called "AI" for short. So I went to the personnel office across the street from the turkey killing plant in this small midwestern town. Latinos, Asians and poor whites filled the waiting room. Everybody wore rubber boots and big, puffy white hairnets--both men and women.
"Bob," the AI boss, explained that the modern turkey business is about the "most high-technical" of all the animal operations. "The turkey is a creation of modern science and industry," he said. "It's been out of the wild only about 1OO years, the last animal to be domesticated. Because of that wildness, it tends to go 'broody,' which means it lays a few eggs once a year and quits. We have to trick it into laying all the time."
Bob told me that the company's birds are much bigger and more clumsy than the original turkey--so much so that they can't breed by themselves anymore. So the company has to use AI to produce the fertile eggs that hatch the chicks that then go into "grow-out" houses and grow up to be slaughtered and processed....

http://www.upc-online.org/fall94/breeding.html​

Ali, A., H. Yassine, O. A. Olusegun, M. Ibrahim, Y. M. Saif, and C. W. Lee. Replication of swine and human influenza viruses in juvenile and layer turkey hens. Vet. Microbiol. 163:71?78. 2013
...
Our results also indicate a potential risk of venereal transmission of influenza viruses in turkeys.

http://www.sciencedirect.com/science/article/pii/S0378113512006967#articles​

And it gets worse:

Avian Diseases 59(1):171-174. 2015
doi: http://dx.doi.org/10.1637/10889-062314-CaseRep
Mature Turkey Breeder Hens Exposed to Pandemic Influenza H1N1: Resultant Effects on Morbidity, Mortality, and Fecundity
Robert Evans[SUP]A[/SUP][SUP]D[/SUP], Yugendar Bommineni[SUP]B[/SUP], Jonathan Falk[SUP]C[/SUP], Adam Blackway[SUP]A[/SUP], Brent Young[SUP]A[/SUP], and Connie Isenhart[SUP]A[/SUP]
...
During the artificial insemination process, turkey breeder hens may become infected with influenza virus acquired from humans.

http://www.bioone.org/doi/10.1637/10889-062314-CaseRep​