same here, i try to prove everything with science and math - but i dont have a good method of "control". i can tell you the observations i have made on my flock with certain changes, and when it comes to feed and medications - i will test different things on a certain group of chickens before i commit my whole flock to it.I am a scientist at heart and research the dickens out of anything I do.
I tend to get annoyed with people here that offer opinion as fact. Their ignorance is not only damaging their birds but the birds of others as well as the integrity of the site.
I do like your info. I will try and find data to support your statements. Bees declines really concern me.
as far as scientific facts to prove medications and modern feeding methods we have to look at the whole picture. you will find all kinds of proof in the lack of nutrition in modern growing methods, whether its GMO or Heritage. here in the U.S. we have to feed alot more people on alot less land. The GMO products produce more, and sometimes better tasting products.
lets think about strawberries, not always - but as a rule of thumb the smaller ones are sweeter than the larger ones from the same plant. most plants somewhat evenly distribute nutrients to all parts, the larger berry didnt get any less sugar, but with its larger mass the sugar is more diluted. the same thing may be happening with GMO products.
most commercial farmers will fertilize with basic fertilizers containing nitrogen, phosphorus, and potash. occasionally they will add chelated (spelling) iron. they don't replenish several other nutrients in the soil such as: gold, molybendium, chromium, and gypsum. people wonder why the bloom end of a tomato goes black, most of the time its lack of calcium in the soil. with better plant nutrition may come better feed conversion, but a severely increased price.
also keep in mind companies like mereck and monsanto are only going to prove with statistics that work for them. if you dig deep enough you may even find lawsuits where someone spoke against them. statistics are easy to "alter" by changing a simple fact. if you take a lab rat and inject it with enough saline or distilled water, i promise you it will have adverse reactions. you take that same lab rat and inject it with arsnic at a small and diluted level, it may not be affected.
for all of these reasons, i encourage people to experiment and share their experiences. i typically dont trust corporate research, and im not sure how far i trust most politicians. if we cant trust each other, who can we trust?