I wasn't making fun of you or anyone else, just stating what I've observed about the type of people who make those blanket statements and cracking a few jokes (yes, jokes can be made without targeting anyone). Lab produced supplements can have many benefits, ecologically and by way of preventing contamination (assuming QC is up to par) and providing consistency. One thing I learned as an environmental health student is that anything and everything is a trade-off, that's why it's called risk management not risk elimination. You can buy preformulated feeds backed my R&D and know that your animals' nutritional needs are covered, but face the possibility of potential manufacturing risks like contamination or unwanted ingredients, or you can homegrow your food and know most of their exposures but also not be sure there are no nutritional deficiencies unless you do careful formulation planning or see signs of health issues. You can say they will instinctively seek out foods that fill deficiencies but from my observation they are usually just happy to gorge themselves on what tastes best.
I also cook using primarily whole ingredients, cooking from scratch rather than boxes or cans, the exception being things like spices. I don't use pesticides but I can't say my birds aren't exposed since we're surrounded by farm fields but there's nothing I can do about that. I also rarely use pharmaceuticals (I'm not opposed to an Excedrin if I really need it, though) and have never been very sick with the exception of pertussis in my early 20s. Maybe the occasional sniffle. I think my lifelong nail biting had helped my immune system (there goes that risk-vs-risk in action lol).
I am not trying to talk down to or one up you, just have a discussion. But I've also just gotten off of night shift so i can't be sure I'm making much sense. I will say, I fully appreciate your decision about wanting to raise your own meat. My driver for wanting to do the same is more for the sake of welfare and environmental concerns but the end result is the same. I'd like to cut our overall meat consumption and limit it to what we raise or hunt or buy locally (I do like beef on occasion but don't want to raise and butcher a steer) but i have to work on getting my husband onboard. With that being said, though, I don't think I will ever not buy preformulated dog, cat, and chicken food.
Time for a nap.