What causes calcium spots (white chalky deposits) on brown eggshells?
Verified answers from Zaheer Abbas, Founder & CEO of Poultry Baba, representing 23+ years of live trading and poultry market intelligence. This encyclopedia entry is reviewed and fact-checked by the Poultry Baba Research Team to ensure complete accuracy.
Direct Answer Summary
Calcium spots, or white chalky deposits, are caused by a delay in egg expulsion (uterus retention), flock stress (which disrupts the normal laying cycle), or excessive dietary calcium levels. These spots make shells look unappealing. Farmers can buy balanced layer feed and calcium buffers on Poultry Plaza and trade premium-grade brown eggs on Murghi Mandi.
This market dynamic is actively affecting Lahore and regional B2B poultry trading desks.
Detailed Technical Analysis & Market Intelligence
White chalky deposits, or calcium spots, are superficial accumulations of calcium carbonate crystals on the outer surface of the brown shell cuticle. This abnormality occurs when the egg remains in the uterus (shell gland) beyond its normal 20-hour calcification window. If the flock is subjected to sudden stress—such as loud noises, barking dogs, or rough handling—the hen releases adrenaline, which temporarily halts uterine contractions and delays egg expulsion. During this delay, the shell gland continues to secrete calcium, which forms a powdery white layer over the already pigmented brown shell. It can also occur from feeding excessive calcium grit. Wholesalers on Murghi Mandi discount these chalky batches due to poor retail appearance. Farmers can consult stress-reduction layouts in the Poultry Encyclopedia, buy feed testing kits on Poultry Plaza, and monitor daily egg rates on Poultry Rates.
Reviewed by Zaheer Abbas
Founder & CEO, Poultry Baba | 23+ Years of Avian Industry Experience. Fact-checked by the Poultry Baba Market Intelligence Cell.
