My aunt, who raised chickens & three batches of quails for a while, used to do it to apparently familiarize the birds with touching/petting of feathers. I stopped doing it just in case. They didn't like it much past the first few times I triedI have never brushed any of my chicks. They instinctively preen themselves to keep clean. Is there some reason you brush them?
You are right! just wasn't expecting them to grow in so fast-everyone elses's seemed to take about five days! They are all pinning quite quickly now and are losing their baby down. They grow so fast.You said your chicks are losing feathers on the edge of their wings? It may be the natural feathering process, they feather up from the wingtips and tails. Mine started to grow pin feathers at the age of 3days. If your chick grooms particularly on this 'less feathered area' you might expect more pin feathers to come.
I'm having a hard time understanding your setup. Do you have any pictures? How many chicks in how big a brooder? How old are your chicks? Are you talking about a white bulb heat lamp?Just wondering, is it appropriate? One of my chicks is losing feathers on the edges of her wings so is there too little room? I can’t fix the white light, we live in rural area and it will take three weeks for a ref light (?red light) to arrive (no Petsmarts or anything to get the right one) so by then they won’t need it. I added two “huts” to try and give them a darkroom if needed.