Wrinkled Eggs
These eggs appear to have ridges or wrinkled surfaces. Overcrowding, which results in stressed hens, can cause this abnormality. It also can be seen when a hen’s shell gland is defective or if the flock has infectious bronchitis. Wrinkles can result in weakened shells. Based on USDA standards for exterior eggshell quality, a wrinkled egg is downgraded to Grade B.