Common Chicken Egg Quality Issues Explained

Blood on the Eggshell 

Spots, traces, or smears of blood on the shell.

Causes Include:

• Ruptured blood vessels in the hen's vagina from straining (common in young pullets and overweight hens)
• Cannibalism or Vent pecking
• Sudden increases in daylight length
• Mite or Lice infestations around the vent

Body-Checked Eggs

These eggs crack during the calcification process, and a layer of calcium is deposited over the crack before the egg is laid, creating groove-like marks on the shell.

Causes Include:

• Incorrect lighting
• Stress
• Age (older hens)
• Overcrowding

Broken or Mended Eggs

Similar to body-checked eggs, these shells crack during calcification and are repaired just before being laid.

Causes Include:

• Stress, fright, or disturbances during shell formation

Calcium-Coated Eggs 

These eggs have an extra powdery layer of calcium on part of al of the shell.

Causes Include:

• Defective shell glands
• Egg remaining in the shell gland to long
• Stress or disturbance during calcification
• Excess calcium in the diet

Calcium Deposits

These eggs have raised, irregular white spots on the shell.

Causes Include:

• Stress during calcification
• Excess calcium
• Defective or immature shell glands

Corrugated Shells 

These shells result from thin egg membranes, often caused by double ovulation. The shell forms over a stretched, uneven membrane.

Causes Include:

• Extra-large or multi-yolk eggs
• Newcastle Disease
• Excessive antibiotic use
• Excess calcium
• Defective shell gland

Lack or Pigment or Uneven Pigmentation

Causes Include:

• Poor nutrition, including deficiencies in protein, minerals, zinc, copper, and manganese
• Viral infections such as infectious bronchitis, Newcastle disease, egg drop syndrome, and avian influenza
• Internal or external parasites (roundworms, capillary worms, red mites)
• Certain drugs, such as nicarbazin in feed
• Hen's age
• Stress
• Egg's prolonged exposure to sunlight and high temperatures

Misshaped or Odd-Shaped Eggs

These eggs may be too large, too small, round instead of oval, or otherwise irregular in shape.

Causes Include:

• Immature shell glands in young hens
• Stress, fright, or disturbances
• Defective shell glands
• Overcrowding
• Diseases such as infectious bronchitis

Mottled Eggs

These eggs have parts of the eggshell that are translucent, sometimes a glassy appearance. Mottled eggs are sometimes thin and fragile.

Causes Include:

• High humidity in the coop
• Certain diseases
• Manganese deficiency
• Overcrowding

Shell-Less Egg

These eggs contain a yolk, albumen, and membrane but no shell. They are most commonly seen in pullets just beginning to lay.

Causes Include:

• Immature shell glands
• Nutritional deficiencies (calcium; vitamins E, B12, and D; phosphorus; selenium
• Diseases such as Newcastle disease, infectious bronchitis, avian influenza, and egg drop syndrome
• Exposure to extreme temperatures or humidity
• Internal or external parasites
• Stress causing premature laying
• Molting
• Exposure to toxins such as mold, fungi, or bacteria

Soft-Shell Egg

These eggs have an incomplete shell or only a thin calcium coating. Providing free-choice oyster shells can help prevent this issue.

Causes Include:

• Immature shell glands
• Nutritional deficiencies (especially calcium and vitamins
• Certain diseases or parasites
• High temperatures and extreme humidity
• Stress or disturbances

Slab-Sided or Flat-Sided Egg

This occurs when two eggs enter the shell gland close together, interrupting calcification of the second egg.

Causes Include:

• Diseases such as infectious bronchitis
• Sudden increases in daylight hours
• Overcrowding
• Stress or disturbances

Speckled Egg

This is when small brown or white speckles appear on the shell.

Causes Include:

• Stress during calcification
• Poor nutrition or excess calcium

Wrinkled Egg

As hens age, egg whites thin, making it harder for the shell to form smoothly.

Causes Include:

• Stress or disturbances
• Diseases such as infectious bronchitis
• Defective shell glands
• Heat stress
• Poor nutrition
• Wrinkled eggs may also indicate a developing Lash Egg

White-Banded Egg

White-banded eggs occur when two eggs are present in a hen's oviduct at the same time and make contact in the shell gland. When the first egg's shell forms, the normal calcification process is interrupted, causing an extra layer of calcium to be deposited and appear as a white band.

Causes Include:

• Stress
• Changes in lighting
• Diseases such as infectious bronchitis

Double or Multiple Yolks

Common in new layers, these occur when two or more yolks are released at the same time.

Blood Spots

Blood spots range from tine specks to larger amounts mixed into the egg.

Causes Include:

• Vitamin A or K imbalances
• Use of Sulphaquinoxaline
• Excess lucerne meal
• Moldy or spoiled feed
• Continuous lighting
• Stress or fright

Pale Yolks

Pale Yolks are caused by a lack of yellow or red pigments in the diet. Hens that eat grass, greens, or corn typically produce darker yolks.

Discolored Yolks

Yolk color is closely linked to diet:

• Cottonseed meal may cause bluish green yolks
• Sheperd's purse weed may cause green yolks
• Certain fatty acids may cause salmon-colored yolks after storage
• Worms or disease may cause pale or "platinum" yolks

Mottled Yolks

Mottled yolks show pale blotches and worsen with long or improper storage.

Causes:

• Certain medications and feed additives
• Nicarbazin
• Raw soybean meal
• Calcium deficiency
• Thin eggshells

Meat Spots 

Meat spots are small pieces of oviduct tissue or broken-down blood spots found in the albumen. They are more common in older hens and are safe to eat.

Thin or Water Albumen

This is common in older hens; eggs are still safe to eat.

Causes Include:

• Diseases such as Newcastle disease, infectious bronchitis, or egg drop syndrome
• High storage temperatures
• High ammonia levels in the coop
• Carbon dioxide loss during storage
• High vanadium levels in feed
• Reactions to certain vaccinations

Off-Color Albumen

• Green Egg Whites may result from high riboflavin levels, bacterial contamination, or improper storage and are not safe to eat.
• Yellow Egg Whites may result from high riboflavin levels or long storage and are not safe to eat.
• Cloudy Egg Whites are common in very fresh eggs or those exposed to freezing temperatures and are safe to eat.