Incubating eggs is an exciting but sometimes stressful journey. I’ll never forget the first time I hatched Silkie chickens—it was both thrilling and challenging! Out of a dozen eggs, I managed to hatch five adorable chicks. Along the way, I learned just how critical factors like temperature and humidity are for successful hatching.
One common issue that can arise during incubation is cracked eggs. While cracks can jeopardize a chick’s development, there are steps you can take to improve the chances of a successful hatch.
Let’s explore why eggs crack during incubation, how to prevent it and what you can do if you find a crack.
Why Do Eggs Crack During Incubation?
Egg cracks can occur for several reasons, including environmental factors, mishandling and the natural development process of the chick. Over the 21-day incubation period, many elements can stress the eggs, leading to cracks.
Here’s a breakdown of the most common causes:
Humidity Levels: Too low humidity causes the egg’s inner membrane to shrink, which can crack the outer shell. Too high humidity weakens the shell, making it prone to breakage.
Temperature Changes: Fluctuations in temperature cause the egg to expand and contract, which can lead to cracking.
Egg Quality: Thin eggshells from poorly nourished hens are more likely to crack during incubation.
Improper Handling: Bumping, dropping or applying too much pressure can damage the eggshell.
Side note, it’s always mind blowing to me to think how a mother hen can sense the humidity and temperature levels, and knows when to turn the eggs and when to leave them be. It’s fascinating and a lot less stressful for the backyard chicken keeper! Haha!
How to Prevent Egg Cracks During Incubation
Preventing cracks is all about maintaining the right conditions and handling the eggs with care. Here are my top tips for a smooth hatching process:
1. Maintain Proper Humidity Levels
Days 1–18: Keep humidity around 50% to prevent moisture loss.
Days 19–21 (Lockdown): Increase humidity to 65–75% to support hatching.
2. Keep Temperatures Consistent
Set your incubator to a steady temperature of 99.5°F.
Use two thermometers to ensure accuracy, as temperature fluctuations can stress the eggs and cause cracks.
3. Choose High-Quality Eggs
Strong shells are key for successful incubation. Ensure hens are fed a balanced diet with access to oyster shells for added calcium.
I use Chicken E-lixir with a high quality calcium source to keep my hens’ eggshells healthy and strong.
Keep oyster shells available at all times to improve eggshell quality with added calcium. I also use Golden Graze treats daily for extra support!
4. Handle Eggs Gently
If your incubator doesn’t turn eggs automatically, manually turn them 2–3 times a day for the first 18 days. This helps prevent the embryo from sticking to the shell and reduces the risk of cracks during development.
Always handle eggs with care to avoid cracks.
What to Do if You Find Cracks in Eggs
Discovering a crack doesn’t always mean the egg is doomed. Here’s what to do if you notice a crack:
1. Assess the Damage
Check whether the crack is superficial or deep. If the inner membrane is intact, the egg might still be viable.
2. Seal Minor Cracks
Use non-toxic adhesive tape or wax to seal small cracks. This helps retain moisture and prevent contamination. I’ve seen success stories using these techniques!
3. Remove Severely Damaged Eggs
If the crack is large or if you suspect contamination, remove the egg to protect the others in the incubator. If it’s a big crack, the chick likely won’t make it.
What Happens During the Hatching Process
As the hatching phase approaches (days 19–21), your incubator enters lockdown, and the excitement begins! Here’s what to expect:
The First Pip: You may hear faint peeping and see a small crack or hole as the chick starts to hatch. This process can take up to 24 hours.
Zipping: The chick will slowly peck around the shell to create a “zipper” pattern before emerging. Avoid intervening unless absolutely necessary—it’s critical for the chick to build strength during this process.
If it’s been over 24 hours and you suspect the chick truly needs help, only then should you consider assisting. First, double-check your humidity levels—they are crucial! Assisting too early can lead to deformities or even death. Most of the time, chicks will hatch on their own. Patience is key!
Successful Hatching Takes Patience and Care
Caring for cracked eggs in an incubator can be stressful, but with the right knowledge and practices, you can improve your chances of a successful hatch. Focus on maintaining proper humidity and temperature, handling eggs gently and selecting high-quality eggs to reduce the risk of cracks.
Incubating eggs is a rewarding experience, and hearing those first little peeps makes it all worthwhile.
Happy incubating!
–The Wing Lady
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