I had 2 chickens, and a fifty or 25 pound bag of layer feed. Since they died,I have a whole bag of feed left. I am planning to buy two more chicks, and I am wondering if I can feed them the layer feed, or is it best to stick with chick feed? I will buy them at two weeks old and should I buy a small pack of chick starter, then in a week or two give them the layer feed?What is the difference between chick start, grower, and layer feed? Thank you for your help!