In my opinion there doesn't have to be a study to "prove" something to me. The proof is in the pudding so to speak. There are many "old farmer's tales" that people today would say, well that is just crazy. But if people actually try some of these things they might find some of them really do work, study or no study. I am not an "old time" farmer but I have used many of their "old time" remedies with great success. And if something like that shows me results when I try it, then I would much rather do that than use some of the very potent animal medications.
An old time farmer told me that if a calf gets the scours (poops) to add a couple of eggs to it's milk for a couple of feedings and it will clear it up, it has worked like a charm every time, I have never had to treat a calf with medications.
An old time farmer told me that vinegar works as a natural preventative for worms. And that garlic powder fed to animals will kill worms. Now I am not saying a little research of our own is not involved here, because maybe garlic isn't good for all animals, as an example of doing our own research.
I bought piglets last year, and like any animal if worms are present you can see signs of it in their waste, these piglets had worms, I added garlic powder to their food each day for a week, no more signs of worms, I soured their milk with vinegar. Never saw another sign of worms and they grew like crazy.
My point is, some things don't make sense, some things have no studies that "prove" it, but the fact of the matter is some of those old time remedies work successfully for some of those that are willing to try them
Same thing with humans, ever heard the story that when you have a bad cough to put vicks vapor rub on the bottoms of your feet and put a pair of socks on, and the cough will stop? Well that has worked for myself and all of my children, how does that work? No idea, does it make sense? Nope.
One time my kids got lice at school, I used the nasty lice shampoo that is "designed" for this, basically a human pesticide. I still found live lice on my kids heads!! My grandmother told me to put vinegar on their heads, and cover with a shower cap. Well it worked no more lice. Vinegar did what that 15.00 bottle of shampoo did not. Sometimes "old farmer's tales" and "old wives" tales are the best way to go, study or no study.
Some of the animal medications are so bad that you are supposed to wear rubber gloves when handling them, if an old farmer's remedy using something safer will give me the same results I am all for it!! Things were definitely done a lot differently in the "old days", but many of those things worked just fine for them, the problem today is everything has been studied and society is becoming dependent on those studies, so now a days with some people if there isn't a study to say it is so, well then it just isn't so. Myself personally I will continue to stick with the old time farmers remedies as long as they work for me, and I will continue to follow advice given to me by people on this forum, they are offering me advice based on their own personal experience and not " the study says".