Egg candling is a crucial technique for poultry farmers and hatchery owners to monitor embryo development during incubation. By using a bright light source, candling allows you to inspect the internal progress of an egg without damaging it. Understanding the different stages of incubation through candling ensures better hatch rates and helps identify infertile or non-viable eggs.
What is Egg Candling?
Egg candling is a method of examining an egg’s contents by shining a light through it. This helps determine if the egg is fertile, if the embryo is developing correctly, and whether it should remain in the incubator.
Best Time to Candle Eggs
Candling should be performed at specific intervals during incubation for optimal results:
- Day 1–3: Not recommended as embryo development is minimal.
- Day 7: First major check to confirm fertility and early embryo growth.
- Day 14: Second check to ensure proper development and identify any non-viable eggs.
- Day 18: Final candling before lockdown; at this stage, a fully formed chick should be visible.
How to Candle Eggs Properly
1. Choose the Right Candling Equipment
- A bright LED candling light or a strong flashlight.
- A dark room to maximize visibility.
- Clean hands to prevent contamination.
2. Steps for Effective Egg Candling
- ➝ Step 1: Hold the egg gently with the pointed end facing down.
- ➝ Step 2: Position the light source at the wider end of the egg.
- ➝ Step 3: Observe the inside of the egg for development.
- ➝ Step 4: Record your observations and remove non-viable eggs.
Candling Eggs at Different Stages of Incubation
Day 1–3: Early Stage
- Little to no visible development.
- The yolk appears as a shadow inside the egg.
- No blood vessels are visible yet.
Day 7: First Major Candling
- Fertile eggs show a visible embryo and blood vessels like spiderwebs.
- Infertile eggs appear clear with no development.
- Dead embryos may have a dark ring (blood ring), indicating early death.
Day 14: Mid-Stage Candling
- The embryo is now larger and moving.
- Blood vessels remain prominent.
- Air sac size has increased.
- Infertile or dead embryos will show no development.
Day 18: Final Candling Before Lockdown
- The chick fills most of the egg with only a small air sac left.
- Clear movement inside the egg.
- Infertile eggs remain clear and should be removed.
Why Candling is Important
- Improves hatch rates by removing bad eggs early.
- Prevents contamination from rotten eggs that could explode.
- Helps identify incubation issues, such as poor temperature or humidity.
- Ensures healthy embryo development for successful hatching.
Common Issues Detected Through Candling
- Clear eggs: Infertile or failed to develop.
- Blood rings: Embryo death due to improper incubation conditions.
- Cracks or abnormalities: Indicates weak or damaged eggs.
Final Tips for Successful Candling
- Always candle eggs in a dark room.
- Handle eggs gently to avoid damage.
- Keep records of fertile and infertile eggs.
- Avoid excessive candling to prevent temperature fluctuations.
Conclusion
Candling eggs at different stages of incubation is a vital skill for poultry farmers aiming for successful hatches. By following a structured candling schedule and recognizing the signs of healthy development, you can ensure strong and viable chicks. Start implementing these candling techniques today to improve your hatch rates and poultry farming efficiency!