Incubating eggs is a crucial step to ensure a high success rate in hatching. It relies on several parameters, including temperature, humidity, egg rotation, and the identification of viable eggs.

The technique of candling is used to assess the viability of eggs. It involves examining the eggs in transparency using a light source to identify signs of development, such as blood vessels. Viable eggs display these characteristics, while non-viable eggs appear clear.

Modern incubators are equipped with automated systems to maintain optimal conditions of temperature and humidity.

Traditional Candling: Why and When to Do It?

Candling is a method that allows the examination of an egg’s contents without breaking it, thanks to a light source.

This technique is primarily used in the context of egg incubation, especially for chicken eggs and other poultry. It is mainly used to assess the viability of eggs.

By illuminating the egg, one can observe the inside and spot signs of development such as the presence of blood vessels. This allows the removal of non-viable eggs before incubation to maximize the hatching rate. Candling is used to detect unfertilized eggs and identify non-viable eggs.

Detecting Unfertilized Eggs

Detecting unfertilized eggs is a critical step in the egg incubation process, whether for poultry or other species. This practice allows the removal of non-viable eggs from the incubator, preventing the wastage of energy and space.

The detection ensures:

  • Energy Savings: Unfertilized eggs should not be incubated. Removing them from the incubator saves energy by avoiding the heating and humidifying of eggs that will not develop into embryos.
  • Space Optimization: By eliminating unfertilized eggs, space is freed up in the incubator for viable eggs, thereby maximizing the hatching success rate.
  • Hygiene and Health: Unfertilized eggs can decompose if not removed. This can create an environment conducive to bacteria and bad odors. By removing them, a clean and healthy incubator is maintained.

The detection of unfertilized eggs is typically done after a few days of incubation, when signs of development should normally be visible. The frequency can vary depending on the bird species. However, it is usually carried out periodically throughout the incubation process to ensure the rapid elimination of non-viable eggs.

Identifying Non-Viable Embryos

In some cases, the embryo may stop developing, which can hinder the success of the incubation. Early identification of these non-viable embryos is crucial to prevent them from rotting and contaminating other eggs. The optimal time for performing the first candling is primarily from the 7th to the 10th day of incubation. At this stage, it is easier to distinguish the blood vessels and developing embryo from non-viable embryos, which remain dark and transparent.

The LaserLife Machine: An Innovation in Candling

This device operates based on LaserLife technology to detect an egg’s viability.

Laser technology has found various innovative applications, including in the field of egg viability detection.

Operating Principle

The machine uses a laser beam to analyze the egg’s viability by projecting this beam through the shell. The operation of this device is based on how the laser beam is absorbed or reflected by the egg, allowing its viability to be determined.

This process is based on spectroscopy, a technique that studies how light interacts with matter. When the laser penetrates the egg, it can detect specific light signals resulting from interaction with the egg’s internal components, such as membranes, fluids, or embryo tissues. These signals are then analyzed to assess the egg’s health.

Advantages of the LaserLife Machine

The LaserLife machine offers various benefits such as precision, speed, and minimization of errors.


The LaserLife machine represents a major gain in terms of accuracy. Unlike traditional candling, which relies on human expertise to detect non-viable eggs, LaserLife technology ensures highly precise automatic detection.


The speed of LaserLife in analyzing eggs is an essential asset for increasing the productivity and efficiency of hatcheries.

Systems established from laser technology, such as LaserLife, are capable of processing large quantities of eggs in record time. This speed is due to the lasers’ ability to perform analyses at high speed and in an automated manner.

In a hatchery, where thousands of eggs can be processed each day, this speed is crucial for maintaining efficient production. Hatcheries can thus minimize delays and maximize their output.

Minimization of Errors

Automation is widely recognized for its ability to minimize human errors.

  • Precision and Consistency: Automated systems perform tasks consistently and accurately, thus eliminating variations due to fatigue or human error.
  • Reduction of Manual Tasks: In the detection process, the machine performs measurements and analyses uniformly, thereby avoiding handling errors.
  • Elimination of Bias: Machines follow objective protocols, ensuring an unbiased assessment.
  • Quality Improvement: The reduction of errors leads to an overall improvement in quality.

Good Practices for Candling

Whether incubation is traditional or assisted by technologies such as the LaserLife machine, adhering to good practices is necessary to ensure the process’s success.

  • Detailed Egg Selection: Choose quality eggs, free of cracks or damage, to maximize the chances of success.
  • Temperature and Humidity Control: Maintain appropriate incubation conditions in terms of temperature and humidity.
  • Regular Egg Rotation: Ensure the eggs are rotated regularly to prevent the yolk from sticking to the shell wall.
  • Preparation for Hatching: Ensure the incubator is ready to welcome the chicks upon hatching, providing the appropriate conditions.


Maintaining a clean environment is essential to reduce contamination risks, whether in egg incubation, food production, or other daily life areas. Here’s how:

  • Regular Cleaning: Establish a regular cleaning schedule to eliminate dirt, dust, and potential contaminants from the environment.
  • Disinfection: Use suitable disinfectants to kill bacteria and germs.
  • Personal Hygiene: Individuals interacting with the environment should maintain good personal hygiene, including frequent hand washing.
  • Proper Storage: Store supplies and food correctly to prevent cross-contamination.


Proper training in the context of traditional candling is essential to guarantee an accurate assessment of egg viability. Trained individuals understand the specific criteria for determining an egg’s viability, such as size, color, consistency, and other characteristics.

Regular Monitoring

Performing regular checks throughout the incubation period to ensure the embryos’ proper progression is a crucial practice in egg incubation.

Regular monitoring ensures that the embryos are developing correctly and increases the chances of successful incubation.


In conclusion, candling is an indispensable step in the egg incubation process, whether for the poultry industry or other applications such as assisted reproduction. Thanks to technological innovations like the LaserLife machine, hatcheries have experienced significant improvements in their hatching rates and operational efficiency.