Opening Failed Eggs – A Systematic Approach to Late Dead-in-Shell Troubleshooting

Opening a failed egg is not simply an exercise in curiosity.

Done methodically, it is one of the most valuable troubleshooting tools available to the poultry breeder.

The aim is not just to discover when the embryo died, but to gather clues about why it died.

Work through the following checks in order.

1. Check the External Pip

Is there an external pip?

If so, is it:

• In the normal position?
• Aligned with the embryo lying correctly?
• Located low along the edge of the air cell?

If the external pip is abnormal, skip to Step 7.

2. Assess the Air Cell

Candle the egg and draw a pencil line around the edge of the air cell.

Compare its size with your staged air cell reference photographs.

This provides one of the most valuable clues to what has occurred during incubation.

Proceed to Step 3.

3. Open the Air Cell

Stand the egg upright in an egg cup.

Carefully tap away the shell over the air cell.

Is the beak inside the air cell?

• Yes — and the air cell is smaller than expected: excessive humidity during incubation is a possible cause. The chick may have been unable to obtain sufficient air after the internal pip.
• No — continue to Step 4.

4. Examine the Inner Membrane

A tightly drawn inner membrane is normal.

By the final stages of incubation, the embryo has absorbed the available fluids in preparation for hatch. Hatcheries refer to this process as drawdown.

A tight membrane is therefore not evidence of "shrink wrapping."

If the membrane remains loose, the embryo probably died at an earlier stage of development.

5. Assess the Embryo

Tear the membrane and examine the chick.

Does it feel:

• Moist?
• Sticky?
• Normal?

Now relate this to the air cell size.

• Sticky chick + small embryo may indicate excessive incubation temperature, which has accelerated development. It may also indicate insufficient humidity during incubation.
• Sticky chick + large embryo may indicate insufficient incubation temperature. It may also indicate excessive humidity during incubation.

No single observation should be used in isolation. Always consider all the evidence together.

6. Check for Malposition

If the embryo appears otherwise normal, examine its position.

Ask:

• Is the head beneath the wing?
• Is it where it should be, beneath the right wing?
• Is another malposition present?

Incorrect positioning is a common cause of hatch failure.

7. High External Pip

Was the external pip unusually high?

If so, check whether the head lies over, rather than beneath, the right wing.

8. Mid-Egg Pip

Is the pip located around the middle of the egg?

If so, consider:

• Were the eggs turned by rolling instead of rocking?
• Was the air cell detached or damaged?
• Were the eggs left unturned during the critical first 24 hours?

These factors deserve careful investigation.

9. Wrong-End Pip

Has the chick pipped through the pointed end of the egg?

If so, review your turning procedures and consider whether abnormal embryo positioning may have developed during incubation.

10. Centre of the Blunt End

If the pip is in the centre of the blunt end, examine the chick's position.

Is the head located between the legs instead of beneath the right wing?

This characteristic malposition often provides another important diagnostic clue.

Don't Stop with the Egg

These are the mechanical checks.

They tell you how the hatch failed.

Your incubation records tell you why.

Once the egg has been examined, review:

• Breeder nutrition.
• Egg storage conditions.
• Temperature accuracy.
• Humidity records.
• Turning method and frequency.
• Ventilation.
• Equipment calibration.

The answers are usually found by combining what the egg tells you with what your records tell you.

A failed egg is not just a disappointment—it is a diagnostic report waiting to be read.

Written by Bob Peel, Greatlander