Concept:Oyster shell meal supplies a rich source of calcium, which breeding hens require to form strong eggshells.
Explanation:Eggshells are composed mainly of calcium carbonate,
CaCO3.
During egg formation, a hen loses a large amount of calcium from her body.
Extra oyster shell meal replaces this lost calcium.
This calcium helps the shell gland produce a harder and more durable shell.
Therefore, feeding oyster shell meal to breeding hens directly supports eggshell hardening.
It does not prevent excess abdominal fat or anaemia.
It also has no effect on shortening the incubation period of eggs.
Answer:C. Aids in hardening egg shell