The mystery of duck egg incubation

Dr. Inge Reijrink M.Sc.

Hatchability results of a duck hatchery fluctuates during the year and the reason for disappointing results are often not clear. One of the most important factor influencing hatchability of duck eggs is the cuticle. A dense cuticle covers the pores of a duck eggshell. The purpose of this cuticle is to protect the embryo against micro organisms. The disadvantage is, that gas exchange like the oxygen flow to the embryo and the escape of carbon dioxide and water vapor from the egg is difficult.

To obtain an optimal hatchability and duck quality, an embryo needs a sufficient amount of oxygen to maximize the use of yolk for body development. The average weight loss of a batch of duck eggs must be around 11% at day of transfer to create an air cell, that contains a sufficient amount of air for breathing between internal and external pipping. In nature, the presence of this dense cuticle is not a disadvantage, because it is partly removed by a surface bacteria (Bacillus Licheniformis) in the first week of incubation.

In artificial incubation this bacteria is not present, and the cuticle remains a barrier for sufficient gas exchange and therefore negatively affects hatchability and duck quality. When gas exchange is not sufficient, hatchability is normally reduced by embryonic mortality in the second half of the incubation process. Most of the dead embryos are small but fully developed, and surrounded by a lot of fluid as a result of too less weight loss and a shortage of oxygen. Download the entire article via the button below.