Causes:
- Badly chilled eggs or eggs overheated or held at too high a temperature.
- Improper incubator temperature at earliest stage of incubation.
- Eggs held too long or held under improper conditions of temperature and humidity.
Correction:
- Protect eggs against freezing temperatures, gather eggs often, cool properly and quickly; hold eggs under conditions recommended by breeder.
- Check accuracy of thermometer. Operate incubator at proper temperature.
- Keep eggs under proper temperature and humidity conditions and set them within seven (7) days after date laid.