Thanks, I hope it helps someone. Did you know they do 'poo transplants' for humans too now? They also manufacture infant feces in pill form for deficient adults. Same principle as an animal eating feces to obtain probiotics, a real lifesaver for some, but sure doesn't sound nice.
Some antibiotics permanently destroy microorganisms and the human or animal can never regain or retain that species, for whatever reason, so in such a case intensive and ongoing re-supply habits like feces consumption may be the only way they can regain the necessary species, albeit temporarily since the host is now a hostile environment to the very probiotics they need to live a healthy life. So they need to continuously replace them because the population is no longer permanently resident and self-replacing.
One good thing about water birds is that their dabbling/feeding methods etc tends to spread saliva between individuals more so than chickens usually will, so that's one more way to regain probiotics. Can spread disease too but then again so do many other things, it's almost unavoidable.
If you have an animal with a known probiotic insufficiency it may help to feed them adequate pre-biotics, to support and feed the good microorganisms. White/refined sugar and overly refined foods feed freeloading microorganisms which like the equivalent of junk food, which also don't supply the host with vitamins/nutrients as a byproduct of their activities, whereas healthier foods are utilized by the beneficial microorganisms and turned into byproducts within the body without which the diet is insufficient no matter what you feed.
Freeloaders can crowd out workers, so to speak, so giving things like raw honey, raw garlic, etc can help feed the good microorganisms, as both garlic and honey contain pre-biotics and honey contains probiotics as well, and both contain natural and harmless antibiotics which won't harm the probiotics but will harm bacterial overloads which harm the probiotics. Many natural foods contain probiotic food, and many things are synthesized within the body into forms we/our animals can utilize, which otherwise we cannot obtain nutrience from.
It's a fascinating subject, I've seen what a 'weak' or 'bad' gut does to a living being, it's terrible, and it all comes down to some not well understood microorganisms and our dependence on them.
Best wishes.
