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Principles of single-stage incubation (3)

Part 3: Optimise your incubation performance by means of weight loss Single-stage incubation allows for precise control of weight loss, which leads to improvements in chick quality. By looking at the natural incubation process of a parent bird, Petersime incubation experts determine the ideal conditions for developing embryos in different stages. With Embryo-Response Incubation™ technology, these conditions can be precisely controlled, resulting in a better hatchery performance.

Roger Banwell, Hatchery Development Manager, Petersime nv

Chick quality

In today’s hatchery industry, both hatchability and chick quality are important. High chick numbers will not always be reflected in high profits. Chick quality and the subsequent post-hatch performance can often be the difference between profit and loss.

Temperature will always be the most critical element in terms of incubation. But it is widely accepted as well that egg weight loss is a vital factor for good chick quality, liveability and post-hatch performance.

Weight loss in multi-stage incubation

In multi-stage incubation, set points for temperature, humidity and ventilation are kept at fixed values due to the ongoing mix of eggs at various stages of incubation, as shown in the figure below. 

Due to the awareness of the potential danger of high levels of COduring certain stages of embryonic development, the ventilation rate is set to a high level. Therefore, weight loss targets are set towards the higher end of the tolerable bandwidth. Because of the high ventilation rate, artificial humidification is required to prevent excessive weight loss.  

This is a clear drawback of multi-stage incubation, because artificial humidification creates temperature differentials and offers an increased risk of contamination. Therefore it should be kept to a minimum. The use of artificial humidification continues throughout the hatching cycle in order to avoid dehydration of the chicks.

Weight loss in single-stage incubation

The advent of single-stage incubation has resulted in the freedom to obtain optimum weight loss in a desired profile.The only restriction is avoiding certain levels of COat key stages of embryonic development.

To determine the optimum weight loss profile, one has to look and replicate the action of the brooding parent bird. Monitoring the activity of a parent bird showed the following different stages:

  • 0 - 36 hours: Rapid turning and warming of the eggs resulted in a uniform warm-up and releasing of stored CO₂.
  • 37 - 216 hours: High attentiveness on the nest resulted in maintaining consistent temperature and limiting fluid and gaseous exchange.
  • 217 - 468 hours: Greatly reduced time on the nest with only regular temperature sensing activity and decreased turning and egg re-location resulted in an increased rate of fluid and gaseous exchange.
  • 433 - hatch: Limited activity until the first chick vocalises (entering of the air cell). Afterwards high attentiveness of the parent bird on the nest, creating stimulus to the other eggs within the clutch. 

The next step is replicating the conditions that the parent bird creates in the nest inside an incubator. This resulted in a weight loss profile that was equal to the natural weight loss profile. This profile is shown on the figure below as the ‘Weight loss profile single-stage incubation’.

Multi-stage incubation results in a linear weight loss profile since the humidity is kept constant during incubation cycles. In single-stage incubation, weight loss is kept to a minimum during the first half of incubation and is increased during the second half of incubation. This results in a non-linear weight profile, as is the case in nature.

The critical element is always weight loss at point of hatch. By using the non-linear weight profile, the target of 12% weight loss at transfer is no longer needed. More efficient and effective is to run the hatchers without artificial humidification for the first 36 to 48 hours and achieve additional weight loss at this stage. This is shown in the figure above where one can clearly see that more weight loss is obtained in the hatcher for single-stage incubation in comparison with multi-stage incubation.

Only during the chick holding period; the period when most of the chicks have hatched, there is a potential need for artificial humidification.

Embryo-Response Incubation™

The Petersime Embryo-Response Incubation™ system replicates the natural process of incubation. This methodology requires no artificial humidification up to the point of hatch and ensures natural gaseous exchange levels for vascular development and hatch stimulation.

Embryo-Response incubation™ leads unmistakably to an increased hatchability and better chick quality. But this approach needs a change in the mindset of the traditional multi-stage users. This technology has meanwhile clearly proven its value and contribution in the hatchery industry.

Dynamic Weight Loss System™ of Petersime automatically monitors and controls the weight loss of the eggs during incubation.


Egg weight loss is an important factor for chick quality, liveability and post-hatch performance. By replicating the natural weight loss process, a non-linear weight loss profile is obtained without the need for artificial humidification. Petersime Embryo-Response Incubation™ technology automatically adjusts incubation parameters to create the optimal environment inside the incubator. This results incontestably in a higher hatchability and better chick quality.