I got a backyard poultry mag Apr/may 2008 issue volume 3 number 2 and was simply amazed at what I learned about apple cider vinegar! You mix 1 tsp with a quart of the chickens drinking water and it's suppose to Improve fertility, give them better health, help clean plumage, help the respiratory system AND it's also a natural fly repellent/deterrent! Put in in a spray bottle and spray it in the coop! Does NO harm to your chickens at all! It's used for organic chicken farms all the time Using this regularly in your chickens water supply can reduce the use of antibiotics. YOu can also treat skin irritations with a diluted mixture of 10/1. This is an awesome magazine with many helpful tips! I will use the vinegar treatment in my hen house over fly repellent any day! Just thought this would be helpful to someone looking for organic treatments!