Probable Cause Corrective Measures High incubation temperatures Follow recommended incubation temperatures. Low incubation humidity Follow suggestions to correct insufficient humidity. Excessive ventilation Reduce vent openings to restrict but maintain adequate air exchange. Holding chicks in hatcher too long after hatching Remove all chicks as soon as fluffy but within 24 hours after hatching.

Troubleshooting: General Problems

Sign: Dead embryos; 3 to 6 days of incubation; yolk sac circulatory system present, embryo on left side, no egg tooth. Causes:

1. Lack of ventilation, or sealed shells, carbon dioxide >1%.

2. Improper turning -- <1/h or >6/h; improper turning angle.

3. Vitamin deficiencies -- vitamin E, riboflavin, biotin, pantothenic acid, or linoleic acid.

Sign: Dead embryos; 7 to 17 days of incubation; each embryo has egg tooth, toenails, feather follicles (8 days), feathers (11 days). Causes:

1. Improper incubator temperature, humidity, turning, ventilation. Low humidity increases
    abnormalities of aortic arches (13 days).

2. Contamination.

3. Nutritional deficiencies -- riboflavin, vitamin B12, biotin, niacin, pyridoxine,
    pantothenic acid, phosphorus, boron, or linoleic acid.

4. Lethal genes (>30 have been described).