When does a layer hen's calcium absorption peak during the egg formation cycle, and when is the best time to feed large-particle limestone?

The physiological demand for calcium in a laying hen is highly cyclic. Shell calcification begins approximately 10 hours after ovulation and peaks during the night, about 12 to 18 hours post-ovulation, when the hen is not feeding. During this nocturnal phase, her intestinal calcium absorption capacity peaks. To meet this demand without depleting her bones, farmers must supply large-particle limestone (2-4 mm) in the afternoon feed (around 3:00 PM to 4:00 PM). These larger particles are retained in the gizzard and slowly dissolved by acid overnight, releasing calcium into the bloodstream exactly when shell calcification is occurring. Fine limestone, on the other hand, is absorbed too quickly and excreted before it can be used. Farmers can study digestive calcium kinetics in the Poultry Encyclopedia, buy high-solubility coarse limestone on Poultry Plaza, monitor daily egg prices on Poultry Rates, and trade premium-shell eggs on Murghi Mandi.