Improving Egg Production and Hen Health with Calcium
Published on Jan 1, 2017
· DOI :10.1016/B978-0-12-800879-9.00030-5
Abstract Calcium metabolism and turnover in egg-laying hens is extraordinary when compared to mammals because of its role in forming the shell of the egg. A shell contains 2 g of calcium, which corresponds to 10% of the hen’s total body calcium. If a hen lays 280 eggs in a year, she will secrete a phenomenal quantity of calcium into her eggshells that is equal to about 30 times of her total body calcium reserve. This chapter describes egg formation, bone architecture, and how a hen struggles to maintain calcium homeostasis by using calcium from feed and bone. Repercussions of a negative calcium imbalance include cage layer fatigue and osteoporosis, conditions whereby the skeleton becomes weak due to loss in mineralization of structural bone. Genetics, exercise, and nutritional manipulation are identified as strategies for maintaining calcium homeostasis in sexually mature female, laying hens.