Humidity in Incubator is the most important thing to maintain correctly together with the temperature. Poor incubator humidity results in damaged eggs or interrupted hatching. Embryos fail to develop or even die when the humidity in the incubator is not right.
The eggs can hatch but the chicks would have deformities and can eventually die. With this article, we will discuss what humidity, what is its role in incubating eggs, and how you should maintain the right humidity level for your eggs.
What is humidity in Incubator?
Generally, humidity is the amount of water vapor present in the air. Humidity plays a major role in animal and plants survival. When incubating eggs, humidity control prevents excess loss of egg moisture. Humidity is the most difficult of the controlled variables in egg hatching and therefore is commonly misunderstood.
Experts in the poultry industry still debate on the specific humidity level required for hatching eggs. But the majority agrees that it should decrease below 25% or above 60% between setting and three days before hatching. We have what we call a lockdown period which is the last three days prior to hatching.
By this time, the humidity level should increase to 70-80%. The increase in humidity helps the chick to avoid getting stuck to its membrane which is just inside the eggshell when they break out and hatch.
There are two ways to measure the humidity level and you need to understand the difference between the two. First is the Relative Humidity (RH) expressed as a percentage. RH is “a measure of the amount of vapor in the air compared with the maximum that could be absorbed at that particular temperature.” This is the reason why RH is expressed in percentage. This simply means that in incubation temperature, the air inside the incubator has half of its likely water vapor volume. Percentage RH level decreases when temperature increases but no additional water was provided.
The next way to measure humidity is using wet bulb temperature. It is “the temperature (in degrees C or F) of a thermometer with a moist cotton wick around its bulb.” Evaporated water cools down the bulb related to humidity just like when you feel cold after a shower. The difference between wet bulb temperature and air temperature is important. Wet bulbs don’t work well in almost static air conditions.
Effects when Humidity Too High in Incubator
There are a few factors why humidity is too high in an incubator. First is the surrounding environment. The humidity in the area where your incubator is located directly affects the incubator. You can always check the humidity of the environment using psychrometer or hygrometer. You can easily access every day’s humidity via search engines like Google weather report. There are also apps that you can use to track humidity per hour. Second is a human error where the operator failed to provide the right humidity level.
Egg shells are naturally porous just like as our skin has pores. The water passes through those pores so all eggs eventually dry out as it releases water from the inside. The humidity level determines the amount of water loss in the egg. So if the humidity is too high, the eggs dry out slower than with low humidity level.
Eggs have airspace at its round end where we usually crack it when we peel it. This airspace gets bigger when the egg losses more water. The airspace plays a big role in the chicks’ development because it is where it breathes. It also allows the chick to develop and move inside so it can position itself into hatching place.
So if the humidity is too high, the airspace will not be large enough for the chick to breathe and move. As a result, the chick will have difficulty breaking out of the shell because of little space. Too high incubation humidity level dies because they just pipped or just broke one part of the egg and its beak got stuck in there. The chick dies due to lack of air and it got weaker and weaker before it was able to get out of the shell.
Because of the pressure inside the egg, the chick’s bill sticks out too far the first hole it created, eventually preventing the chick to make the counter-clockwise bill chipping movement from shells inside. And then its mucus dries out and the bill got stuck in the hole.
On the other hand, low humidity level results to a small chick with big airspace when it’s their time to hatch. Because they are too small, they are weak and die even before, during or just after they hatched.
How to Maintain Humidity in Incubator
There is a simple way to measure RH indirectly and look at its direct effect on the egg. The process is weighing the eggs to monitor water loss during the incubation period. Most birds need to lose around 13-15% of their weight from the time they were set in the incubator up to the hatching. It is possible to check if the water loss rate is too high because of the high humidity or too low because the humidity is low. To do this, take the average weights and compare it to its expected weights.
To illustrate, you can refer to the table below. Take the average weights every three to four days and plot them on the graph. Now, if the eggs’ average weight is lower than the expected, you need to increase the humidity level and vice versa. You can intervene immediately the incubation process as you notice for any deviation in the eggs’ weight. The ultimate goal is to reach the ideal weight loss when the hatching day comes.
How to Decrease Humidity in Incubator
High humidity in the incubator can have harmful effects on the egg and chick development. The simplest and easiest way to decrease humidity is to open the incubator’s ventilation. Then remove the water from the incubator.
In case your poultry is located in a naturally humid area, then air is possibly highly humid too. For this case, you’ll need to buy a dehumidifier for the incubation room or put more dehumidifying materials in the incubator. Best natural dehumidifiers are rice and paper towels.
Here are more tips to control the right humidity in the incubator:
- Replace the water with an ice block if the humidity level is too high when there is water but low when there’s no water.
- Go for automatic humidity control systems if you don’t like to manually check it from time to time.
- Don’t open the incubator when the actual hatching for the last 1-2 days. By this time, humidity level may abruptly decrease and it will take a long time to raise it again.
The right level of humidity in incubator combined with right temperature level dictate the success of egg hatching. If you are into the poultry business, it is really worth investing time and equipment to properly monitor the humidity level especially of the first and last days of incubation. Do you have more incubating tips you want to share? Comment them below.