As a hatchery manager, I am sure you have encountered a time where you must store eggs longer than you want due to various reasons. We know this increase in storage days will negatively impact our hatchability and chick quality. So, what can you do to help improve the situation that you are now facing?

With traditional storage methods, you will not prevent a reduction in hatchability or chick quality but help slow down this deterioration rate. The first thing you can do is reduce the temperature in your hatchery egg storage room.  As we store hatching eggs for increased lengths of time, we lower the temperature and raise the humidity. Doing both of these not only helps to preserve the embryo stability but preserves the integrity of the yolk and albumen while reducing moisture loss through the shell.  

The chart featured in the image is typically recommended for the hatchery egg storage room based on days of egg storage and the temperature of the oldest eggs you are holding. This is by far the easiest way and typically what most people do if they are storing eggs for a longer period. 

In incubation, the term hatch window is used quite frequently. The hatch window is described as the time between the first surge of chicks hatching and when the hatching process is completed.  This should be 20-24 hours, which is the same as what happens naturally under broody hens.  In commercial incubators, It can be found using the humidity reading on a hatcher and by incubation equipment software. Hatch window is important in order to identify if the hatch is being pulled at the correct time and if the temperature and humidity are adequate in the setters and hatchers. It also shows whether these two parameters, along with the ventilation, have been uniform during the entire incubation and hatching process.

There are several factors that can influence the hatch window.

• Breeder characteristics- health status, age, and genetic line
• Characteristics of the eggs- shell conductance, egg size, storage days and level of embryo development when the eggs are set
• Environment of the eggs- temperature, humidity, ventilation uniformity and stage program (which includes the breeder farm, egg transportation, storage room and incubation process

Here is a “handy” tip from the Hatchery Consulting Team.

We all know how important turning eggs is to proper machine operations and to the developing embryo. But how can we easily determine turn angle in our setters? If you can’t tell if you have a good turn angle use your fist!

Your fist should fit between the vertical tray support bars. This is roughly 4 inches, which should be close to a 45-degree turn angle. Works in both single-stage and multi-stage Jamesway and Chick Master machines.

No tool bag required.

During the incubation process, an egg needs to lose sufficient moisture in order to create an air cell where the embryo will make its first pip where it will begin pulmonary respiration. The ideal moisture loss is approximately 11-12% at the time of transfer, or an average 0.6% per day (Single Stage incubation ideally should be 9-10%)

When chicks are hatching with inadequate moisture loss, the problem can disguise itself as incorrect incubation temperature, humidity or ventilation issues as well as others. When eggs achieve the proper moisture loss, the air cell should occupy about 1/3 of the egg at transfer.  Location of pipping on the eggshell is another good indicator of proper moisture but can, at times, be subjective.  Proper air cell size is important for the 18-day old embryo to be orientated in the correct position for pipping and hatching. If the air cell is too small, this can impede the developing chick from attaining its ideal position, consequently the chick will have difficulty locating the air cell during the pipping process. If the embryo is not able to internally pip into the air cell, the embryo will not be able to complete the external pipping process and will most likely die.

If you’re unsure how to obtain the proper moisture loss, follow this formula:

% Moisture loss = Full egg tray weight at set – Full egg tray weight at transfer X 100

Full egg tray weight at set – Empty egg tray weight

All too often we find hatchery equipment calibrations being performed with instruments that have not themselves been calibrated for a long time or ever. The hatchery equipment does not know it is out of calibration and is trying to maintain the desired set points, therefore the equipment is maintaining an incorrect set point, causing hatchability and quality issues. Without verifying the calibration instruments themselves, you can chase and troubleshoot the wrong solutions, trying to solve the hatch issues.

For proper analysis of hatch results, we need to accurately identify a fertile and an infertile egg. Remember, embryo growth will begin at the site of fertilization, or the germinal disc, and will continue to grow outward in an organized manner to form a ring, or donut shape. An infertile egg will maintain a tight, compact appearance at the germinal disc on the yolk.

If you have a high number of clear eggs from a flock or rack/buggy, it doesn’t mean the eggs are infertile. Remember not all clear eggs are infertile. However, if ’clear eggs’ are greater than 2.5-3%, this will need to be further investigated.

Possible causes of clear eggs: Infertile, very early embryonic mortality, Egg handling issues (Eggs held improperly – temperature fluctuation, rough handling; Eggs held too long; Too much egg fumigation), This can be a point of contention between the hatchery and breeder departments. However, what is truly important is the determination of fertility or not. If we have good fertility from a breeder flock, then we can troubleshoot other areas such as egg handling practices. If we just assume it is a fertility problem, we will never get to the root cause of the clear egg issue and poor hatch. So, it is extremely important to verify whether we have a fertility problem first, then begin to troubleshoot the egg handling practices thereafter.