I am new to dual purpose birds and am waiting to see what sex they will end up. I was out watching them today after they were fed and watered and I noticed my Black Australorp hen (99% certain its a hen) hobbling a bit and trying to stay off one leg. She wasn't moving that much preferring to rest more. After a while she was running around again and I was thinking she was better, but shortly after she starting playing and running around she began hobbling again. I am curious now on just what to do. Any suggestions? Also, I am confused as to what to feed my chickens and if I should get them some grit. I spoke to different people and everyone says something different. One guy says to feed them the same grower feed as my meat kings, some say to feed starter for 4 months then switch to layer feed. When I asked about grit, I was told not worry about grit, and someone else told me that there is calcium in the layer feed so they didn't need grit. I thought the grit was to help digest food and they needed it. And I also thought the calcium was for egg production. I was planning on buying them some "normal shells" at 25% the cost of oyster shells, which I thought served two purposes, help in digestion and egg production. What is the best way to feed my chickens for optimum health and performance? And at what ages do I change feeds?