Why Some Chicks Struggle To Hatch

There are several reasons why some chicks don't break out of their shell. Firstly, it could be due to improper humidity levels during incubation, causing the membrane inside the shell to dry out and stick to the chick. Additionally, reduced humidity can cause shell membranes to dry out, limiting the chick's movement and ability to break free. Improper turning or positioning of eggs on the hatching tray can also lead to this issue. Furthermore, it is suggested that low temperatures may be a factor, as fresh eggs stored at the proper temperature are crucial for a successful hatch. Other factors, such as egg storage time, turning frequency, and breeder nutrition, can also contribute to a chick's ability to break through the shell. While it can be tempting to help a struggling chick, it is important to carefully consider the risks, as intervening can lead to further complications and may require long-term care for the chick.

Low humidity during incubation

The humidity level during the incubation of eggs is crucial as it influences the embryo's heat loss through evaporation, which in turn affects embryonic mortality and development. Low humidity during incubation can cause the membrane to dry out and become too tough for chicks to tear through, a condition known as "shrink wrapping". This results in decreased hatch rates, with the chicks unable to break out of their shells.

To understand this, it is important to know how humidity is measured. Humidity is calculated by measuring the water vapour in the air, specifically the Relative Humidity percentage (RH%). The RH% measures the current water vapour content relative to the maximum that could be absorbed at that temperature. Therefore, when using an incubator, both humidity and temperature must be considered together. For example, raising the temperature without adding water will cause the RH% to drop.

The optimal humidity level during hatching is crucial for successful chick hatching. For most bird species, humidity needs to be higher at hatching than during incubation. A humidity level of at least 60% RH is recommended during hatching to prevent the membrane from drying out.

Studies have shown that low RH during incubation increases egg weight loss and embryonic mortality while decreasing the hatch rate of fertile eggs. Maintaining the eggshell temperature at 37.8°C and incubating eggs at a low RH can lead to a decrease in the hatch rate of fertile eggs, but it has minimal impact on chick quality or post-hatch performance.

Additionally, low humidity during incubation can be corrected later by increasing the humidity level. However, this method is not always effective, as the humidity will only rise briefly before the small water droplets on the eggs evaporate. It is crucial to monitor the humidity level and make adjustments as needed to ensure successful chick hatching.

Incorrect positioning of eggs

The positioning of eggs during incubation can influence the hatching process and chick quality. Incorrect positioning of eggs during incubation can lead to hatching failures.

During the first phase of incubation, chicken eggs are typically placed vertically with the air cell up. In contrast, during the hatching phase, eggs are positioned horizontally. The air cell should remain on the fat end of the egg, which is slightly elevated when laid by chickens.

Some sources recommend that eggs be turned at least three times a day during incubation, with a 90-degree rotation over the course of the day. For example, a 45-degree tilt to the left followed by a 45-degree tilt to the right. This can be achieved by gently rolling the eggs or using egg turners or incubators with tilting trays or rotating racks.

Additionally, the age and health of the breeding flock can influence hatching success. For example, very young males may have lower sperm counts, leading to infertility. Similarly, eggs from older hens may have a higher incidence of infertility, early embryo mortality, and late hatches.

Opening the incubator during hatching

The success of a hatch depends on many factors, including temperature and humidity. Opening the incubator during the process can let heat and humidity escape, which can, in turn, affect the hatch. Therefore, it is recommended to only open the incubator when necessary.

The last three days before the chicks hatch are particularly sensitive. During this time, the humidity is raised to 70-75% to help the chicks get correctly oriented for hatching. Opening the incubator during this time can lead to a drop in humidity, making it difficult for the chicks to break out of their shells. Consequently, it is generally advised not to open the incubator during these three days.

However, some people do open the incubator during the lockdown phase to address specific issues, such as refilling the water tray. If you need to open the incubator during this time, it is recommended to do so quickly and use hot water to refill the tray, so the temperature and humidity can be restored faster. Additionally, it is advised not to leave the incubator open for an excessive amount of time.

While some people believe that opening the incubator during the lockdown will ruin the hatch, others argue that it is not a hard and fast rule. They claim that as long as the necessary precautions are taken, it is possible to open the incubator without causing any issues. However, it is important to carefully consider the risks and be prepared to provide extra care in case the chick that is helped to hatch has special needs.

Weak chicks

A chick that is unable to break out of its shell may be too weak to complete the task. The process of breaking out of the shell is an exhausting one, and some chicks simply do not have the strength to complete it. This could be due to a variety of factors, such as malpositioning in the egg, a dried-out shell membrane, or insufficient humidity in the incubator.

Malpositioning in the egg can occur when the pointy end of the egg is higher than the blunt end during incubation, or when eggs are turned while the chick tries to reposition itself before hatching. If the air cell is not at the blunt end of the egg, the chick may not have enough room to turn its head and break the shell. In such cases, the chick's head may be trapped under its left wing or between its legs, making it impossible for the chick to break free.

A dried-out shell membrane can also hinder a chick's ability to break out of its shell. The membrane should be translucent white; if it has dried out, it will turn a parchment tan colour. To remedy this, the egg can be wrapped in a warm, damp washcloth to gently moisten the membrane. However, it is important to avoid dripping water into the pip, as this could drown the chick.

Insufficient humidity in the incubator can also cause problems for hatching chicks. Opening the incubator to assist a chick can further reduce humidity, impacting the other chicks in the incubator. It is important to carefully consider the risks and potential consequences before deciding to intervene in the hatching process.

While it can be tempting to help a struggling chick, it is important to remember that interference could lead to defects or other long-term issues. If a chick is taking an excessive amount of time to hatch, it may be best to consult a veterinarian or seek guidance from experienced poultry keepers.

Low temperatures

Maintaining the correct humidity during incubation is crucial for successful chick hatching. Low humidity can cause the egg membranes to dry out prematurely, hindering the chick's ability to break free from the shell. In some cases, the chick may become stuck to the dried-out membrane, requiring assistance to free itself.

It is important to monitor the temperature and humidity levels during incubation and make necessary adjustments to ensure optimal conditions for hatching. While it is generally recommended to maintain high humidity levels, excessive humidity can also cause issues, such as a sticky nest, which can hinder the chick's hatching process.

Additionally, low temperatures during storage can delay the hatching process. For every day of storage under suboptimal temperature conditions, the hatching time can be delayed by approximately one hour. This delay can disrupt the natural hatching timeline and potentially impact the chick's ability to break out of its shell.

In cases where chicks are struggling to break out of their shells due to low temperatures or humidity issues, providing assistance may be necessary. However, it is crucial to proceed with caution, as intervening can carry risks. For example, attempting to help the chick escape the shell may accidentally cause bleeding or even death. Therefore, it is essential to carefully assess the situation and consider seeking guidance from experienced sources before taking any action.

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