Goose eggs must be incubated in order to hatch. The eggs gestate for 29 to 31 days and need a temperature of 99 degrees, a wet-bulb thermometer humidity reading of about 88 degrees, and frequent turning. Without an artificial incubator, or the body of the mother goose, the only way to replicate these conditions involves a surrogate bird mother. A broody chicken can successfully incubate a goose egg with her body and a little help from an overseeing human.
Incubating and Hatching Goose Eggs
Make sure the nest box rests in a secure, sheltered and private location, whether in a secluded pen in a barn or garage, or in a broody house. Put the chicken food and water near the nest box, but far enough away that the hen will have to leave the nest to eat and drink. She needs to leave the nest for about fifteen minutes a day, for her health. This short time away from the nest does not harm the eggs. Place the goose egg(s) in a single layer inside the nest box.
Add the broody chicken to the pen or coop, but let her discover the nest by herself. She should soon settle herself in to begin setting (begin sitting on the eggs all day every day until they hatch). She will then only leave the nest long enough to eat and drink each day.
Consistently supply the chicken with fresh water, food and some grit.
Turn the egg(s) over twice daily, because a chicken is too small to be able to turn the large goose egg(s) sufficiently. If no one turns the egg, the yolk will stick to the shell and the gosling inside will die.
Mist the egg(s) with warm water from the spray bottle once daily. This is necessary because goose eggs require more humidity than chicken eggs to hatch. Under a goose, the eggs would receive this from the water on the mother's feathers after she has returned from swimming.
After 29 to 31 days, the egg(s) should begin to hatch.