Regular layers will eat untill they are full. CornishX...the meat birds, will gorge themselves all day and all night. If you have regular layers...just keep the feeders full 24/7
what about treats such as watermelon, bread, etc.. they love that stuff.. how often should i feed thme that, and garden tomatoes ,etc.. i dont wanna OVERFEED em.
Do your chickens free range? If so, typically they will find their own good dietary mix....and so they will start ignoring the treat if you give them too much...
If they're in a pen, without other sources of foof besides feed and treats, then I'd say, Treat them like treats. A little each day is ok...but don't let them gorge on it.