I read somewhere that when you pickup your chickens, you should not feel the breast bone too much, but instead feel their meaty breasts. Not so with my chickens, I can distinctly feel their breast bone without trying. (I have never held any other chickens, and I'm new to this). I recently lost two chickens, so I'm now concerned the other two are also unhealthy. Please tell me how I can improve if there is a problem. I keep a mix of about 50% organic grain, and crumbles in their food dispenser at all times. I let them free range for about three hours a day in the evening. We treat them with bread, and toss in leftover veggies and fruits sporadically. As for water, it comes from a rain barrel, which I throw a tiny tablet of chlorine in about once a month to keep the algae out. Does the brand of crumbles/pellets matter? They used to be on Purina, but I switched to a cheaper kind, but it is supposed to have all the stuff birds need.