Getting poultry off of the ground and onto roosts reduces the chance of cloacal contact with infected fecal matter. Turkeys and other poultry will huddle together and sleep on the ground in absence of a suitable roost. The direct contact from huddling greatly increases the chance of Blackhead transmission as the birds defecate through the night.
All of our birds have roosts available to them, and we basically let chickens be chickens and turkeys be turkeys. This also means that most of our turkeys spend the night roosting in trees. We have a perimeter fence, a guardian dog, and llamas to protect all of our livestock from predators. Modern recommendations for raising meat birds (chickens and turkeys) say that if birds roost, their leg meat will not be as tender, although we have never found this to be true. I also suspect that commercial producers don't want to provide roosts because that would cost money, and if you're raising 100,000 birds, that's a lot of roosts.
Fecal-cloacal transmission as the main source of outbreaks also explains why people who raised their turkeys inside on wire had better luck with avoiding Blackhead. The poop falls through the wire, so the birds are less likely to sit in it.
Frequently moving the flock to fresh pasture minimizes the amount of manure and exposure time that the birds are subject to the pathogens shed in the manure. . . . Reducing the number of birds in a given unit of area (acre, paddock, etc.) has an effect similar to moving the turkeys to fresh ground.
While commercial producers measure their stocking rate in square feet -- like one bird per square foot or less in confinement -- our 50+ chickens and nine breeding turkeys have access to about ten acres, although most of them don't range much farther than two or three acres. Still, 60 birds on two acres (88,000 square feet) would be 1,467 square feet per bird. When I think of 40,000 birds on an acre -- inside -- all I can think about is how much that would stink!
Ultraviolet light from sunshine, the drying action of wind, the heat of summer, and the chill of winter are all detrimental to the survival of H. meleagridis. Any natural weathering process that breaks down poultry manure -- and therefore the hospitable niche of the Blackhead pathogen -- should be encouraged. H. meleagridis requires moisture to survive and spread, and moving the flock to dry ground makes the spread of disease more difficult.
In other words, turkeys confined to buildings are sitting ducks for infections. Our turkeys are outside almost 24 hours a day. They only go into the chicken house to grab a little grain, then they're out again.
The fascinating thing about recent research regarding Blackhead is that they have discovered the worst transmission is actually fecal-cloaca rather than fecal-oral, which is how people assumed turkeys contracted it, since that is how most animals get most diseases that have anything to do with parasites. In the September/October issue of ALBC News, Spencer said:
When the turkey is given a constant supply of food, experiments have shown that the Blackhead protozoan is not capable of surviving stomach acids and, therefore, Blackhead is not usually acquired when the turkey eats or drinks. Turkeys that have liberal access to food and water can't get Blackhead orally unless they eat cecal worm eggs.
And when turkeys are free ranging, the odds of that happening are pretty slim. Maybe one bird could get it, but it would not run rampant through a flock. Also, when turkeys are free-ranging, they are eating constantly, compared to birds confined, which are eating grain (also known as "concentrates") off and on through the day. If they are not eating, the acid level in their stomach goes down.
I don't think it is a coincidence that Blackhead became a problem at the same time that industrial agriculture was getting geared up and starting to confine birds. Open Air Poultry Houses For All Climates was published in 1912 trying to convince farmers to stop putting their chickens inside. It cites evidence of sickly birds in confinement and zero mortality in birds that were given free range. Unfortunately, the runaway train kept going, and more and more farmers kept locking up their birds. Spencer said the U.S. turkey production fell from 11 million birds in 1890 to an average of 3.7 million annually between 1910 and 1920.
Of course, some people think we can control all of this with drugs by feeding turkeys a medication that will prevent Blackhead or constantly deworming chickens that live with the turkeys. But drugs are not sustainable. All of them eventually stop working when they're overused. We've seen it with antibiotics in people and with dewormers in goats and sheep.
In the most recent issue of ALBC News, Spencer says that there are reports of Blackhead-resistant turkeys:
This strategy is only plausible for heritage turkeys (i.e. not broad-breasted whites or bronzes) as the heritage birds can be bred and selected for resistance. If a Blackhead outbreak occurs in a heritage flock, the surviving individuals may have some trait, either genetic or behavioral that increases their chance of surviving or avoiding a Blackhead infection.
This is the sustainable answer. Whenever we get into a fight with nature and try to beat it with drugs, we always lose eventually. Scientists thought they had completely defeated internal parasites in sheep and goats 20 years ago, and vets were recommending monthly deworming. Today, the parasites have grown resistant to the dewormers, and on some farms, there is nothing that works when the animals really need it. The one or two goats I lose to parasites every year is nothing compared to the reports of breeders losing 20% of their flocks and herds in the southeast U.S. annually.
Maybe without even knowing it, I've developed a Blackhead-resistant flock. Or maybe by letting turkeys do what comes naturally -- like run around and roost in trees -- I've created an environment where they can thrive naturally.
If you are interested in preserving heritage breeds of livestock, even if you don't own any, I highly recommend joining the American Livestock Breed Conservancy. Every other month, they put out a very informative newsletter about rare breeds, and they have an annual conference. They are also responsible for doing an annual census to check the status of rare breeds. It is largely due to their efforts, as well as some very dedicated breeders, that heritage turkeys are not extinct now, as there were only a few thousand of all breeds combined in the late 1990s.