Day 4 to 11: regulate based on RH

Day 4 to 11: regulate based on RH

On day 18, the hatching eggs must - on average - have lost 10-12% of its weight (depending on type and age of the parent stock). This is on average about 0.6% per day. If the hatching egg has lost less than this amount, there is a risk that the chick will drown. A breakout analysis will show a fully developed chick but a very tiny air cell. The embryo needs the air cell for its transition to oxygen uptake through its lungs (respiration). If the air cell is too small, the chick will experience problems. In this case, the embryo often suffocates at pipping (it cannot find the air cell).

Relative humidity (RH) and CO2 Under high RH conditions, the egg loses less moisture. This leads to a smaller air cell (less available oxygen at internal pipping). Under low RH conditions, the egg loses more moisture so its air cell increases in size. Heat transfer is less in dry air, which increases the risk of overheating, and an associated increase in CO2 production. An air cell meter allows you to measure the size of the air cell in individual eggs. However, it is common practice to weigh an entire setter tray with eggs to calculate the average moisture loss between day 0 and day 18, which is then used as the basis for your climate settings. LOOK-THINK-ACTcopyright protected

What is happening here?

The graph clearly shows when the ventilation inlets are opened: The RH and CO2 values decrease sharply at those moments.