for what, exactly?
Young chicks? No.
Roosters? No
Hens, of laying age? Depends if they are eating anything at all besides layer feed. Depends if they are willing to eat crushed eggshells as a calcium supplement. Depends whether the calcium content of your soil is adequate for their additional calcium needs. Depends if they free-range. Depends if you feed treats, and whether those treats have adequate calcium levels for laying hens. Depends if any hen is laying thin, weak or shell-less eggs.
A lot of people take the approach that offering crushed oyster shell, free choice, to laying hens gives each hen the opportunity to eat whatever extra calcium she may need, whenever she needs -- based on her current diet and health conditions. Thus, helping to safeguard against problems like internal egg breakage (which is fatal), and excessive egg-eating of crushed and broken eggs in the nest.