I feed all my Silkies a 18-20% protein flock raiser, gamebird grower or unmediated chick starter to everyone with oyster shells on the side. I always have more non-layers (broody, recovering broody, young pullets, chicks and roosters) that don’t need calcium. Also, Silkies are slow to mature usually not laying until around 7 months old and not prolific layers. On average I get about 14 eggs from a hen before she goes broody, then recovering from being broody about 6 weeks with no eggs if she doesn’t hatch chicks longer if she broods chicks then they start the cycle over. So I just feel like they don’t need a lot of extra calcium. I don’t feed organic because it’s not popular around here so most of the time the available bags are older than I like to buy. I like my food to be manufactured within 4 weeks of purchase. As far as brands I like nutrena or poulin grain. I used to be able to get southern states flock balancer and that was my go to but lost the distributor up here.