Answer:

Oyster shell is not so valuable as is generally supposed.

Its chemical constituents are similar to those of the egg shell as regards lime compounds particularly, and the feeding of oyster shell is supposed to aid in producing material in the hen for forming the shell of the egg. Oyster or other similar shell is not necessary when proper food is given.

It is supposed to prevent the laying of soft shelled eggs, but the laying of such eggs is generally controlled by conditions over which the feeding of oyster shell has no influence.