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Natural hatching process

Looking towards nature and to the activities of the parent bird before, during and after the complete incubation process has always been a driving force behind the Petersime philosophy. Embryo-Response incubation™ technology is based on this principle. Synchro-Hatch™ gives the embryo the same signals and stimuli as it would experience from the attentive mother bird in nature and thus offers optimal hatching conditions.

Roger Banwell, Hatchery Development Manager, Petersime nv

Activity of the brooding hen

There have been numerous studies that show the activity of the broody hen. The changes in feeding practice, brood patch creation and increased clucking are just a few examples. Generally, these studies concentrate on the relevance and effect on the maternal factor with respect to the parent bird.

The majority of these studies refer to the rapid increase in nest occupation during the last 3 days of incubation. The hen will not leave the nest. It is not surprising to see the nest soiled, because the hen will relieve herself in the nest regardless of the eggs and ensuing chicks. The level of clucking will also increase after air cell entry and prior to external pipping. This is commonly considered as a communication form between the parent bird and the hatching chick.

This interaction between the parent bird and egg is often overlooked from the perspective of the embryo that is trapped within the confines of the encompassing shell.

Hatching triggers

During the hatching phase, the parent bird returns to the nest and sits on the eggs for the majority of the time. This will affect the rate of gas diffusion, the moisture exchange and the heat dissipation. Communication of the parent bird with the embryo is established at the air cell entry stage and the activity of the parent bird changes accordingly.

Stress is often wrongly assumed to be always a negative factor. In nature, stress can be positive as a biological or developmental stimulus. Any athlete or surgeon will testify that stress can be essential at key moments.

Optical and audio faculties are functional in the chick after the entry of the air cell. Several studies have shown significant reactions and responses when varying these elements. Further investigation is necessary to use these parameters to guide the hatching process.

Hatch timing

A common misconception is that a parent bird can ensure a clutch of 6 eggs to hatch within a few hours. This is not saying that the parent bird doesn’t do an incredible job. Laying eggs over several days in variable conditions and still hatch them together in a relatively good time and at a uniform quality requires some advanced abilities.

However it is not unusual to see a hatch occur over a period of 2 days. During this period, the parent bird must restrain the hatched chicks whilst waiting for the remaining eggs to hatch. Typically, the lack of audio response from the unhatched eggs after the increased parental clucking, acts as the signal for the parent bird to leave the nest.


The observed activity and signals of the parent bird during the natural hatching process have resulted in the development of Synchro-Hatch™. This technology mimics the conditions experienced by the hatching eggs in the natural nest environment. Therefore Synchro-Hatch™ ensures a narrow hatch window and good chick quality and uniformity.

It should be stressed that it is wrong to say that Synchro-Hatch™ delays and/or forces the hatch to occur. Correct is to say that Synchro-Hatch™ gives the encapsulated chick the same signals, stimuli and positive stress that it would naturally expect in the nest from the parent bird and thus offers the optimal hatching conditions.

Synchro-Hatch™ sensor which interacts with the incubation program of the BioStreamer™ hatcher


Studies have investigated the interaction between the parent bird and the embryo during the hatching process. Petersime has observed these natural signals and applies this principle in an industrial hatcher by means of Synchro-Hatch™. This technology has meanwhile proven its worth and impact on chick quality, uniformity and the subsequent post-hatch performance in the hatchery industry.

One thing is certain: the parent bird does not sit back and watch the hatch happen. She intervenes and undoubtedly interacts with the entire process.