The rising demand in commercial layer and parent stock performance increases pressure on the birds to metabolize and mobilise more calcium from the intestine to the bones and uterus for eggshell production. The skeletons and dietary requirements of hens are unique relative to the level of calcium intake and the capacity of bone that is constantly being built and resorbed. The eggshell is formed from calcium carbonate, and the layer will metabolize and transport the total weight of her skeleton several times to produce eggshells during the course of the laying cycle. The hen requires approximately 2.5g calcium in around 20 hours to produce a fully developed egg of 60g. About 60 to 70% of the required calcium can be provided via the feed which is not enough to cover the peak in calcium requirement during eggshell formation. All the rest has to be metabolized from the bodily reserves which is a unique but delicate system. Creating and maintaining a strong skeleton by assuring the provision and availability of essential nutrients is vital to ensure a productive laying hen.
