OK i am pretty confused about this whole feeding thing now, my chicks are about 12 weeks old. so what feed should they be on, can they be put on layer mash or do they need grower? also i was at the feed store and they have 16% layer and 20% layer what is the diffrence and which is better? and we are coming into winter so should i give them cracked corm or scrach? can someone explain the diffrence between all the diffrent feeds (including game feed)?