Layer feed is good for layers, not so good for juveniles or Roos. That is when it is recommended to feed flock raiser or something with a calcium level less than 2% , with calcium carbonate on ' free take ' for the layers that require it.
Oyster shell is also known as ' calcium carbonate ' . It's a good idea to have a bowl in the run , under cover, for ' free take ' . Calcium , phosphorus and vit D3 are of the utmost importance for layers, however if you have Roos and young birds in your flock , too much calcium in the feed can...