Oyster Shell

Ah, yes, the almighty calcium intake. Women need it, men need it, and so do chickens! 

Calcium is the primary mineral that makes up eggshells.  When the calcium is absent in the hens daily diet, she won’t have the basic nutrients and materials to make the shell. Thin egg shells occur when calcium (oyster shell), phosphorus (legumes, grasses and bugs) and vitamin D3 (feed grade supplement) are not provided in diets at the proper levels.   If you note thin egg shells becoming prevalent in nesting boxes, provide oyster shell free choice so your girls can ingest the calcium at times when they are not especially hungry - but know instead that they need to supplement their calcium supply.

Oyster Shell needs to be available once your chickens reach 18 weeks of age, and should be continued throughout the life of a laying hen.

Providing oyster shell free choice is a good method and should continue the life time of a laying hen. 

There’s a bit of discrepancy over whether oyster shell is best given ‘free choice’ or mixed into the food much like a granola combination. Frankly, I do both. Whether you provide oyster shell mixed in with feed, separately in a non breakable dish or pan or scatter on the ground like treats – just make sure they get it.