I love this thread and this idea – working through some version of it myself because there's no perfect bedding, and our household produces an enormous amount of coffee grounds, and we love the smell – but there is caffeine in spent grounds.The coffee is “decaffeinated” because it’s already been brewed. If you read through the thread I posted several research articles which used coffee in feed with no positive nor negative side effects. I used it myself for eight months and loved it. I currently use it on the poop boards.
Used coffee grounds are considered decaffeinated because the caffeine is extracted during the brewing process. Again, I’ll reference the research articles noted in this thread as well as my experiences with using it successfully. The chickens don’t eat it.
I’ve used it to read chicks but mama hen was with them. The chickens nor the chicks have ever expressed interest in the coffee grounds. You better buy it while you can because from what I’ve heard chick days will be the only time of year it will be stocked at tsc. I bought every bag they had!
Can't remember why I know this, but here are a few links. I'm not sure if that's a concern if the chickens aren't eating the grounds, but I'd personally be a little sketch on whether it could be absorbed through the skin.
https://www.caffeineinformer.com/caffeine-content/coffee-grounds
https://fullcoffeeroast.com/do-old-coffee-grounds-have-less-caffeine/