I have been putting pepper in my girls feed for about 2 years now and it does work. I have no set amount, I just add what I think is enough to the feed. I just sprikle it on top of the feed. I put vinager and a glove garlic in their water about once a week. Do NOT put this in a metal waterer, it will poison your birds, use plastic or rubber bowls, ONLY. It helps to keep their sinus' clear and also helps to keep lice and mites off of them. I do not have heat or have lights in my coop, nor is their water heated.
I have fed my birds cabbage and onions and never tasted anything different in their eggs. They wont eat the onions. I have been told that cabbage will make the girls infertile, I dont know if that is true or not. Never did a test to see. I have fed all of my birds stuff we have gotten out of dumpsters from the grocery store, meats, cheese, milk, cakes, pies, fruits, veggies, breads, you name it. I have never noticed any different taste in the eggs. Some of the meats I cook and some I give to them raw, like hamburg. I havent had any birds get sick or kill over from being fed any of this stuff. It helps on the feed bill, we go thru 1300 lbs in a month, plus they get lots of vitamins and minerals from this stuff and they LOVE it, when they see me coming with a box of this stuff, they are knocking eachother over to get to me frist, flying up on me, they go nuts over it all.
I hope that all was of some help to you all.................