Ive searched this but need to make sure. I am feeding the chickens Nutrena laying pellets along with daily treats of grains and fruits/veggies. Do I still need to provide them grit? Is oyster shell the same as grit? The run is now officially all dirt. They have been here 3 weeks with no ill effects so far. Also, is Blue Seal better than Nutrena or is it all the same. I was kind of suprised and kind of disappointed at all the additives that are in the pellets although most are vitamins and minerals.