HUMIDITY - CRITICAL FACTOR IN INCUBATION

1. Introduction

If you have ever used an incubator before, you probably know that there are many variables that you need to monitor and pay special attention to during incubation. Science states that there are four primary factors to consider in incubation, which are:

• Temperature;
• Ventilation;
• Turning;
• Humidity;

Of these four factors mentioned, Incubation Specialists state that humidity is the most difficult factor to control and sometimes measure, which is why it is generally misunderstood. Although there is conflicting information on the Internet about the role of humidity, it is very important and essential that this factor is not devalued or removed from the incubation process as a whole.

2. What does humidity do?  

Egg shells appear to be solid, but in reality their surface is porous.

You can test whether a supermarket egg is good to eat by floating it in water. Fresher eggs will sink because they weigh more, while old eggs will float because they have much more empty space inside them. This also applies to the eggs you are trying to incubate, although we do not recommend a float test for hatching eggs.

While eggs are incubating, they will naturally lose weight. It is important that your humidity is set at the right percentage so that the eggs are losing an optimum amount of weight. If the humidity is kept at the right level, the developing chicks will be able to use the available air space to breathe and move around properly.

3. If humidity is too low

Low humidity will cause the eggs to lose too much weight, which means the air space will be larger than what is ideal. A large air space also means that the chick will be smaller than normal. Small chicks are weak chicks, and weak chicks cannot always hatch on their own, and they may die shortly before or immediately after hatching. 

It should be noted, however, that low humidity is typically less of a problem than high humidity.

4. If humidity is too high

If low humidity equals excessive weight loss, then high humidity equals insufficient weight loss. In this case, the air space will be smaller than normal, and the chick will be larger. A large chick may be a strong chick, but a small air space can affect the respiration and cause problems in this situation. This also causes a lack of space, making it difficult for the chick to move and get out of the shell.

A chick poking through the eggshell that has not lost enough weight can die from weakness due to lack of air or because it cannot move to get free until the hatch is finished.

5. How to achieve the correct humidity levels

As described above, too high or too low humidity will affect the weight loss of the egg during incubation. Therefore, in order to avoid this oscillation, it is essential to have a reliable and quality hygrometer (instrument that reads humidity), because through it the humidity factor will be better controlled. If a breeder does not have a hygrometer or if he is not sure that his hygrometer is accurate, successful hatching rates will naturally be compromised. In a situation where the breeder is using an incubator without a properly calibrated hygrometer, it is recommended that the eggs should be weighed periodically to check their developmental status.

Most bird species (with the exception of the ostrich family) will have lost between 13 and 15% of their weight from the first day of incubation until the day they hatch. By weighing the eggs every few days it is possible to accurately adjust the humidity to compensate for excessive or insufficient weight loss. 

The graph below shows the relationship of incubation days represented along the horizontal X-axis, and egg weight on the vertical Y-axis. You can plot the ideal weight loss from day 0 until hatching, which we show here in red. Then periodically when you weigh your eggs mark your weight on the graph and record (green dots) where it is on the red line.

6. Automatic humidity management

Our Rcom Max and Pro incubator models come equipped with automatic humidity control that makes incubation more effective and efficient. The breeder can adjust the humidity level in the incubator and the machine will automatically manage and control the humidity as required.