Abstract
This is the time of year when wild waterfowl get the nesting urge. And many of them - particularly mallard ducks - are not timid about where they place their nests. They'll crawl under chicken houses and other outbuildings, often a surprising distance from water, to hide their caches of hatching eggs.
No one knows exactly why "Mother Nature" arranged for ducks, other webfooted birds, and various seabirds to be one of nature's main carriers of avian influenza viruses. But, at least, we do know they are. They may not exhibit symptoms of the infection; but their infected droppings can carry high numbers of influenza viruses which can, under optimal conditions, wreak havoc on chickens, turkeys and game birds.
So producers should keep two major points in mind, says Edward T Mallinson, Extension poultry veterinarian at the University of Maryland in College Park.
1. Discourage wild waterfowl from nesting under or near poultry houses.
2. Keep all web-footed birds away from chickens, turkeys and game birds; even domestic waterfowl can be carriers of avian influenz.a.
Dr. Mallinson theorizes that seabirds and waterfowl (web-footed birds) have reached a state of accommodation or compromise with avian influenz.a viruses over many generations. For reasons not fully known - perhaps different basic habitats or genetics - other kinds of birds, such as chickens, turkeys and game birds (quail, guinea fowl, pheasants, etc.) have not reached the same level or type of accommodation.
Medical history has shown many times that when a disease common to one population jumps to a population where it has not been common, the new group can suffer heavy death losses. A good example in human medical history was heavy death losses among American Indians when they contracted certain diseases carried by early white settlers in the United States. A somewhat similar situation appears to exist between webfooted and other kinds of birds.
As a preventive measure against avian influenza, national and international veterinary specialists alike are admonishing farmers these days to practice segregation in their poultry activities.
Keep web-footed birds away from those that aren't web-footed. Even better, make a choice on one type or the other.
You'll probably be better off to specialize in one kind of fowl in order to develop a quality product. The alternative is dealing with a menagerie and its inherent risks of hidden and obvious health problems. •