Incubation and Embryology - University of Illinois

Incubation Troubleshooting

Draggy hatch - some chicks early, but hatch slow in finishing.

Probable Cause Suggested Corrective Measure
Improper gathering, cooling and holding of eggs.

Eggs must be gathered frequently, cooled properly before casing, and held at proper temperature and humidity before setting.

Mixing large eggs and small eggs in the same setting (large eggs are usually from older hens or heavier breeders, small eggs from younger hens or lighter breeders. Larger eggs and older eggs tend to hatch later than small eggs, all other things being equal).

Where possible, try to set eggs of uniform size and age per machine. Larger eggs or eggs which have been held longer frequently give better hatching results when incubated at slightly higher temperature than for smaller or fresher eggs so that development will be roughly equal at transfer.

Hot spots and cold sports due to (1) improper incubator design, or to (2) using cooling water that is excessively cold, or to (3) supplying the incubator with air under too much pressure or air which has not been preconditioned, or to (4) pumping exhaust air out of the machine in a manner which interferes with the machine's own system.

Incubator's optimum functioning can be upset by excessive cold cooling water, faulty air supply, or by attempting to duct out exhaust air improperly.

Improper incubator or hatcher temperature.

Maintain proper temperature levels throughout incubating and hatching cycle.

Recirculating stale, contaminated air.

Ventilate properly, with 100 percent fresh, tempered air.

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