Hi! I have 6 bantam hens (3 brahmas, 2 cochins, 1 d'uccle) that are about 4 months old. Recently I have seen some of them have runny poo and I am wondering if this is a major concern. They eat Dumor Poultry Grower/Finisher and have grit available to them. I feed them blueberries, strawberries, and kale as treats pretty often. Is there anything I need to change about their diet to make them healthier? Any advice is appreciated as I am new to chickens.