I'm not sure where this info came from. It was a university perhaps TN or AL.
I saved it once so I hope I don't get in trouble for plagiarism.
In the last 3 days without a pip the causes in order of importance that seem to apply to you are
- Inadequate turning, resulting in decreased embryonic membrane development and nutrient absorption.
- Humidity too high during incubation or after transfer.
- Incubator temperature too low.
- Hatcher temperature too high.
- Eggs chilled (e.g., at transfer).
- Nutritional deficiencies.
- Heredity.
- Embryological development accident.
- Breeder diseases.
- Inadequate ventilation.
- Prolonged egg storage.