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The hatch window
The hatch window
The hatch window is the period required for hatching almost all the eggs. There are various factors that influence the length of this period. The more uniform the batch and the incubation conditions, the shorter the hatch window. The optimal hatch window for layer hen chicks is 12-15 hours, and 24-32 hours for broilers. Chicks that hatch first run the risk of drying out. Their weight will fall and quality will decline. Keeping the hatch window shorter reduces these risks. You can reduce the length of the hatch window in different ways. Some hatchery managers increase the temperature a little during the hatching process. Wet chicks cool themselves and the surrounding eggs. Increasing the temperature prevents this effect. This stimulates hatching but increases stress among the chicks. Other hatchery managers decrease the ventilation a little, which leads to a higher CO2 concentration. The embryos experience a shortage of oxygen and are triggered to pip into the air cell and break out of the egg. Decreasing the ventilation prevents cold air entering the hatcher (which can delay hatching). Both methods work easily, quickly, and efficiently, but the question remains whether this is better for chick quality or not. The shorter the hatching period, the higher the uniformity in hatching egg temperatures has been. With a uniform batch of eggs and uniform incubation conditions, 95% of the chicks hatch within 24 hours. All the factors that delay or accelerate the incubation process can lead to the hatch window being 36 hours or even longer. A small spread in the hatch window also means the day-old-chicks are all at the same stage of development at the time of dispatch. This makes it easier to set climate and other conditions correctly in the house before the chicks arrive. Ensure the climate in the hatcher is optimal for the hatched chicks, so they can stay in the hatcher for a while without any problems. 100 min. 75% hatched 90 12 hours before pull time 80 40 50 60 70 max. 25% hatched 24 hours before pull time 30 20 10 Hours to pull time Hatching forms a classic S-curve. A few early chicks hatch first, then the largest group follows quickly, and the last chicks arrive in slow spurts. This graph gives a rough guideline. The shorter the period, the better.
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Broiler hatch window
Pull time: 95% hatched Hatchability (%) -32-30-27-24-21-18-15-12 -9 -6 -3 0 0copyright protected
-32 hours -24 hours -12 hours Pull time
The duration of the hatch window determines the pull time and in turn that of the first feed. The chicks do not need feed and water immediately, but you cannot have an optimal first-feed period for all the chicks if the hatch window is too long.
Duration of hatch window and timing of the first feed
early mid late Optimal time for feed and water
early mid late Optimal time for feed and water
Short hatch window Optimal period for all chicks Long hatch window No optimal period for all chicks possible
