Guide to egg abnormalities and how to solve them

Producing quality, fertile eggs is the objective of every broiler breeder, both as a mark of their professionalism and to maximise their economic return.

With this in mind, breeding company Aviagen has produced a new pocket guide for farm managers, identifying a number of the most common egg shell abnormalities that cause poor hatchability.

The guide describes the most likely causes and suggest possible solutions.

“The text in this new pocket guide is deliberately clear, concise and simple in order to provide a quick reference point,” says global head of technical transfer Nick French. “This allows the farmers to have all the information they need when they are confronted with problems on the farm and an invaluable tool to optimise performance.”

The following is a selection of the more common abnormalities found on farm:

Floor eggs Floor_Egg

Possible cause 1: Insufficient nest space

Solution: Allow maximum of four birds per nest or 40 birds per metre

Possible cause 2: Birds not using nest boxes

Solution: Introduce perches at 28 days in rear

Ensure no barriers to nest boxes such as feeders/drinkers

Uniform light distribution of 60 lux+

Walk house six to 12 times a day, to remove floor eggs

Possible cause 3: Birds having to choose between eating or going to nest

Solution: Provide enough feeder space and manage feeding times well

Blood on shell Blood_on_Shell_1

Possible cause 1: Damage to cloaca due to sexual immaturity/over stimulation

Solution: Use recommended lighting/feeding programmes

Possible cause 2: Aggressive behaviour

Solution: Ensure proper stocking density, feeder space and male:female ratio


Small eggs Small_Egg_1

Possible cause 1: Birds moved too early to open-sided houses

Solution: Use blackout blinds and do not transfer before 18 weeks

Possible cause 2: Lighting too early

Solution: Delay transfer and delay light stimulation

Possible cause 3: Poor flock uniformity

Solution: Use flock grading to establish a CV of less than 10%


Faecal contamination

Possible cause 1: Nests are not cfecal_contamination_egglean

Solution: Change or top up nesting material every 10 days

Possible cause 2: Infrequent egg collection

Solution: Collect eggs at least four times a day

Possible cause 3: Faeces on egg collection systems

Solution: Clean or sanitise at least weekly

Possible cause 4: Feed is contaminated

Solution: Monitor feed samples for signs of drugs or mycotoxins


Cracked/punctured eggs Puncture_Hole

Possible cause 1: Egg collection/packing system causing cracks

Solution: Check for any rough transfer points

Possible cause 2: Too many birds per nest

Solution: Allow maximum of four birds per next or 40 birds per metre

Possible cause 3: Mechanical nests not run often enough

Solution: Run at least three times a day, to clear eggs from nests


Abnormal shaped/wrinkled eggs Misshaped

Possible cause 1: Disease

Solution: Check for Newcastle Disease, IB and Egg Drop Syndrome

Possible cause 2: Incorrect vaccination

Solution: Check the vaccination programme is suitable for the area

Possible cause 3: Poor biosecurity

Solution: Train all staff in best practice


Thin shelled eggs Thin_Shell

Possible cause 1: Incorrect nutrient levels

Solution: Analyse feed for calcium, phosphorous and vitamin D

Possible cause 2: Disease

Solution: Check for mycoplasma and ND, avian influenza, EDS and IB


Double yolk eggs Double_yolked_egg

Possible cause 1: Light stimulation has occurred too early

Solution: Delay transfer and delay light simulation until birds are sexually mature

Possible cause 2: Overfeeding into peak

Solution: Follow the recommended feeding programme


Pale/white eggs pale

Possible cause 1: Possible disease

Solution: Check for usual diseases and check vaccination programme

Possible cause 2: Feed contamination

Solution: Prevent cross-contamination in feedmill and maybe add vitamin C


Calcium deposits Calcium_Deposits

Possible cause 1: Calcium in diet too high

Solution: Check samples and stick to recommended doses

Possible cause 2: Disease

Solution: Check for infectious bronchitis


Slab sided eggs Slab_Sided_Egg

Possible cause 1: Old flock

Solution: Replace with younger birds

Possible cause 2: Excessive flock disturbance

Solution: Minimise loud noises and activity around house

Possible cause 3: Incorrect stocking density

Solution: Avoid overcrowding as birds age


In total, the Aviagen pocket guide covers 12 different conditions, with more detailed advice for broiler breeders. It can be downloaded from the Aviagen website

See more