Why does a sudden drop in house lighting intensity below 10 lux cause a permanent reduction in brown layer egg production?

The reproductive cycle of a laying hen is light-dependent. Photoreceptors in the hen's hypothalamus (located deep in the brain) respond to light energy that penetrates the skull. This activation stimulates the release of Gonadotropin-Releasing Hormone (GnRH), which in turn triggers the pituitary gland to secrete Luteinizing Hormone (LH) and Follicle-Stimulating Hormone (FSH)—the hormones mandatory for follicle development and ovulation. For commercial brown layers, the minimum light intensity required to trigger this neuroendocrine pathway is 10 to 15 lux. If the light intensity inside a tunnel house drops below 10 lux (due to dirty light bulbs, dusty lens covers, or poor bulb layout in caged rows), the hypothalamus perceives it as "winter darkness" and halts hormone secretion. This initiates an involuntary reproductive rest phase, leading to a permanent drop in lay rate and early molting. Installing dust-proof LED lights is essential. Farmers can study photoperiodism math in the Poultry Encyclopedia, buy high-intensity LED systems on Poultry Plaza, check daily rate trends on Poultry Rates, and list laying flocks on Murghi Mandi.