Answer:

Calcium deficiency can result in soft-shelled eggs, so be sure you provide the added calcium supplement in the form of egg- or oyster shell always fed in a separate container from the feed, so each hen can eat as much or as little as she needs.

Explanation:

As a hen ages, the eggs that she lays get gradually larger. However, the calcium content deposited in the shell remains the same despite the size of the egg. So, the eggshells become thinner as the hen ages