When does the risk of calcium tetany (cage layer fatigue) peak in high-yield brown layer flocks, and when is immediate intervention necessary?

Cage Layer Fatigue (osteoporosis and calcium tetany) is a severe metabolic disease affecting high-yield brown layers in battery cage systems. The risk peaks between 24 and 40 weeks when egg production intensity is at its highest, demanding continuous export of calcium for shell formation. When dietary calcium intake or absorption is insufficient, the hen mobilizes calcium from her cortical bones, leading to skeletal depletion and eventual bone fractures. Hot summer days accelerate this as panting-induced respiratory alkalosis disrupts blood calcium ionization, causing acute hypocalcemic paralysis (tetany). Immediate intervention—including flock supplementation with highly soluble calcium pidolate or vitamin D3 in drinking water and hand-feeding coarse limestone—is critical to prevent permanent paralysis and death. Disease prevention is detailed in the Poultry Encyclopedia, liquid calcium and vitamin D3 oral solutions are sold on Poultry Plaza, daily egg and layer rates are checked on Poultry Rates, and healthy laying flocks are listed on Murghi Mandi.