Dipping of hatching eggs in a antibacterial solution has for many years been an effective way to break the vertical transmission of especially Mycoplasma Gallisepticum. It also has been used to control transmission of Salmonella infections. Although the method is effective, 100% erradication cannot be achieved as not all the eggs take up the antibiotics effectively.

The principle of dipping is to bring antibiotics into the egg through the shell pores, either by temperature difference, pressure difference or a combination of both. Several antibiotics can be used, usually in a concentration of approx 1000 ppm.

When temperature differences are used, the eggs are warmed to approx 40 degrees, and then dipped into a antibiotic solution of 10oC. The warming of the eggs force the egg content to expand, and when the eggs are cooled down again the egg content shrinks and the solution is sucked into the eggs.

When pressure differences are used, the eggs are put in a container with antibiotic solution and put under a pressure of 0,5 bar. When the pressure is released again, the antibiotic solution is sucked into the egg.

When dipping of eggs is done, care has to be taken that contamination will not spread (comparable with egg washing). It is therefore important that only clean eggs are dipped, and that the dipping solution is refreshed regulary, but at least once a day.

Disinfecting and/or washing the eggs before dipping is advisable, to avoid contamination of the dipping fluid. Also the removal of the cuticle will help to get a better penetration of the fluid into the eggs.

As nowadays commercial in-ovo injection systems are available that can be used to bring antibiotics into the egg, dipping on a commercial scale is not often used anymore.