What is the importance of the incubation phase in terms of chick quality?

The setter combines two phases: the creation of all structures and organs and the further growth and differentiation of organs and tissues. It lays the foundation for chick quality. A number of factors are crucial during this process, namely the availability of O2, CO2 and water drainage, turning over the egg, the optimum embryo temperature, and heat transmission in the form of air speed and relative humidity. If something is wrong with just part of this equation, it is immediately visible in the chick quality.  

What is the impact of temperature in the setter?

Temperature is important at every step of the chick’s development, from its early organ development, through its later growing phase. The temperature affects which genes are expressed and how enzymes perform.

High temperatures accelerate the embryo’s metabolism, which means more O2 is required. At a certain point unlimited O2 is no longer available, as the eggshell simply cannot let any more through. The embryo will then have problems with its energy supply, which directly affects – for instance – the development of the heart. This has been very clearly demonstrated by the results of the PhD project of Dr. Roos Molenaar and Conny Maatjes.

When you have uniform conditions in the setter, you minimize the hatch window. Since chick development proceeds in a very systematic way, the hatch window will also be consistent between one egg and the other. So the foundation for the hatch window is already laid in the setter. 

Why look at embryo temperature instead of machine temperature?

100°F (37.8°C) is the optimal temperature for embryo development. But what really matters is what the embryo experiences. During the first nine days, the embryo’s heat production is still very low, so it is important to add heat. After these nine days, heat production increases, so the external temperature needs to be reduced. In short, the temperature of the air in the machine doesn’t necessarily say anything about your embryo temperature.

The design of the incubator and the combination of, for instance, air temperature, RH and air density determine the correlation between embryo and air temperature. The embryo temperature should lead the rest, not the other way around. If the conditions in your incubator are very uniform, you can adjust for air temperature. But even then, the temperature profiles must be derived from the right, optimum embryo temperature. The adjustments made to air profiles all have to do with the optimization of embryo temperature. 

What does the eggshell temperature tell you?

When you measure embryo temperature, you have to sacrifice an egg, and that’s a pity. That’s why we decided to investigate the relation between eggshell temperature and embryo temperature. You can generally say that in the starting phase when the embryo produces little heat and you are providing warmth, the eggshell temperature is higher by a few tenths of a degree Fahrenheit. Later in the process, it is the other way around as the eggshell temperature drops somewhat below that of the embryo, since the egg is being cooled down.  

How do you achieve a uniform air flow?

Air speed, air flow, cooling and heating are important factors to consider when it comes to optimum embryo temperature. There are on average 100,000 eggs in a machine, and each embryo needs to be at the optimum temperature at each stage of the hatching process, regardless of whether it is placed in the back corner or in the middle.

To ensure that no matter where the eggs are placed, we developed the principle of cooling and heating per section – laminar airflow. This diverts the air before it reaches the egg. With laminar airflow, the air also flows straight ahead after every cart through perforated radiators.

The humidifying system (as well as the temperature it emits) also plays a role. The best kind of humidity comes from the eggs themselves. So you need to keep the doors tightly closed to create a uniform humidity. We call this gas-sealed incubation.

Pride in my work

'While I was studying at Wageningen, the topic I focused on was cattle. It was only at the end of my studies that I came into contact with poultry. When I started going deeper into the subject and started learning about hatching processes, it proved to be really interesting! Because of my newfound interest in the hatching process, I ended up at HatchTech. I still find it pretty extraordinary that a beautiful little yellow chick is created from a small clump of cells in just three weeks. The broiler industry is sometimes a subject for debate, at least in the Netherlands. At HatchTech, we try to create innovative solutions in which the quality and well-being of the chick comes first, and I’m really proud of this.' 

Tremendously complex

'There is still so much to be discovered! The creation of chicks seems simple, but it’s actually a tremendously complex process that can be affected by over a thousand different factors. There’s still a lot that isn’t known yet, and there’s still so much to improve on. The culture of HatchTech also appeals to me – it’s an innovative company, and you’re free to explore the things you find interesting. There are hardly any boundaries.'