The viral mutations that continue to occur, are perpetuated by mixing species, and should be avoided only adds to reason why birds of different species should not be mixed together. There's an old saying,"An ounce of prevention is worth a pound of cure".
The bit above is a statement I agree with, but I think it does depend on your setup, the amount of space you have, and the value of your lines. If I kept only rare heritage breeds or rare species e.g. some pheasants, I'd be a darn sight more careful. But I keep mongrels, and I mix them, as does the average poultry keeper around here. Works for some, not for others.
As for the opinions of the other sites you listed, personally, I disagree with them. They're stating absolutes about more complex issues than can be covered in one sweeping declaration. Doesn't mean their opinion, or yours, are invalid opinions; certainly they're true for the majority at least, but my personal opinion is that they're not true for some cases.
My stance is not based on 'something read on a blog' or whatever, but on personal experience with my own animals, as well as other first-hand experiences with other people's animals. The right animals are easy to keep together. The wrong ones, impossible. The issues can range from temperament to disease issues, the factors are many and variable.
But I overall agree, it's certainly not for everyone. For probably the majority the cons outweigh the pros, and it's not feasible for the average person with the average setup. I wasn't trying to recommend newbies try it, in case you thought so.
It's not correct to refer to only one method of poultry husbandry as being the right one and all others irresponsible; this forum is devoted to all kinds of poultry keepers with many differing schools of thought on the matter. When we cannot agree we must agree to disagree; you and I already know we don't see eye to eye on many things, as previous threads show.
There are actually pros to cross contamination of various things, within reason of course, as alien as that may sound; particularly under a more natural method of animal husbandry wherein artificial/conventional aids are not employed, so natural immunity is gained instead; after all the global ecosystem is not naturally under biosecurity controls of even a minute fraction of the extreme extent many humans practice, and excessive biosecurity contributes to the virulence of viruses, bacteria etc... No species naturally lives in isolation. Animal species are continually mixing under natural circumstances. The main control there is population density, and of course natural selection which can't happen to many domestic animals. That said many people already practice some kind of stand-in artificial 'natural' selection that takes into account susceptible individuals and prevents them from breeding.
Even from a disease perspective, there's two sides of the coin, each suited to a different husbandry method; there are pros for both chickens and turkeys when cohabiting, including greater disease resistance; for one example, chickens gain resistance against some types of Marek's Disease via exposure to turkeys carrying their type of it. Good for those practicing more natural husbandry methods including breeding for further resistance, but useless for those separating and vaccinating as a rule and culling all symptomatic birds. What's right for one situation is not right for all.
It does depend on circumstances and it's probably not workable for most, many people do make it work and don't have problems.
For crowded situations, separation is usually best because the pathogen and parasite load is heightened by high population density, obviously, and such animals are often lacking in other ways, weaker, and therefore more medicated, and in turn they're breeding tougher viruses/bacteria etc in weaker birds, which can spread like wildfire and eradicate whole flocks.
For a large, sprawling farm, cohabitation-related pathogen/parasite adaption and overpopulation is nowhere near the same threat level, and behavioral issues are also far less likely to be a serious issue. These free range, cohabited animals may present a threat to non-cohabited caged animals, but the same is true in reverse, and you don't cull the stronger to protect the weaker. We're directly responsible for much of the virulence of modern diseases and bacteria, not cohabitation.
Quote: I think you've misunderstood my statement there, I'm referring to whether or not a given animal is able to be trusted to live with others without attacking them. Until proven innocent, guilty, at least in my estimation. It basically just means that I assume they're dangerous with other animals until proven otherwise.
Best wishes.
