When does eggshell pigment deposition take place in the shell gland, and when can physical disturbances cause pale brown eggs?

The rich brown color of brown eggs is due to the pigment protoporphyrin-IX, which is synthesized and deposited by the shell gland (uterus). This pigmentation process is highly time-specific, occurring almost entirely during the final 3 to 4 hours of the 24-hour shell formation cycle, immediately before oviposition (laying). If the hen experiences physical disturbances or stress (such as loud noises, vaccination handling, or dog attacks) during this critical 3-to-4-hour window, the adrenaline release triggers premature uterine contractions or delays egg laying. This causes the pigment to be deposited unevenly, resulting in pale, blotchy, or white-patched eggs. Physiology guides are in the Poultry Encyclopedia, calming herbal feed additives and stress-relievers are sold on Poultry Plaza, daily premium egg rates are updated on Poultry Rates, and high-pigment egg shipments are traded on Murghi Mandi.