Probable Cause Corrective Measures High average incubation humidity Follow recommended incubation humidity. Check size of air cell as an indicator for adjusting humidity condition. Low incubation temperature Follow recommended temperature settings. Lethal genes Avoid cross breeding. May need to secure different breeding stock. Inadequate ventilation Increase ventilation rate in incubator and/or room, but avoid drafts. Improper fumigation of eggs Fumigate eggs by following the procedure carefully.

Troubleshooting: General Problems

Sign: Dead embryos; >18 days of incubation. Causes:

1. Improper incubator temperature, humidity, turning, ventilation.

2. Improper hatcher temperature, humidity, ventilation.

3. Contamination, especially from molds (aspergillis, etc.).

4. Fumigation too severe or too prolonged.

5. Eggs chilled in transfer, or transferred too late.

6. Broken shell -- pre-set, during incubation, or at transfer.

7. Nutritional deficiencies -- vitamin D, vitamin A, folic acid, or pantothenic acid,
    riboflavin, vitamin E, selenium, vitamin K, biotin, thiamin, vitamin B12, calcium,
    phosphorus, manganese, or linoleic acid.

8. Embryonic malposition; embryo fails to move into proper hatching position (see #21).

9. Embryological development accident. Failure to change to lung respiration and all
    intra-embryonic circulation, and/or to retract the intestinal loops and yolk sac.
    These and other changes are critical at this time.

10. Heredity -- lethal genes, chromosome abnormalities.

11. Twinning.

12. Hatcher opened too much during pipping and hatching.

13. Poor shell quality.

14. Breeder diseases.