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The time when you remove the baskets from the hatcher is called ‘pull time’. You do this when virtually all the chicks have hatched. There will always be stragglers but waiting for them will compromise the chicks that have already hatched. And you always have to question whether they are viable (or are they eggs that will not hatch?). The hatchery manager then checks whether the chicks are dried off well enough. A good guideline is to have only 5% of the chicks still with damp neck feathers. This can be difficult sometimes, because the eggs do not all hatch at the same time. If the chicks hatch very irregularly, some will have dried off too much, while others are still too wet, which causes them to cool too fast. We refer to this as a long hatch window. The chicks should not remain in the hatcher baskets for too long after hatching because they will overheat (the hatcher cannot maintain a low enough temperature). If pull time is later, there will also be more variation in chick quality. Future legislation is likely to stipulate a maximum period a chick can be without feed or water or a maximum interval before it arrives at the poultry house. But which point in time is the baseline measurement? From the moment the first chick hatches? In this case it will be even more important to keep the hatch window as short as possible. Leaving hatched chicks in the hatcher for a little while. It is always preferable than placing them outside the hatcher in unsuitable conditions, as this would cause more damage.
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Chicks dry out fairly quickly, an individual chick takes about 3-6 hours. For an entire batch, the target pull time is 18-20 hours after the humidity peak.
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A chick is still wet when it is freshly hatched. If you observe about 5% of the chicks with moist necks, the pulling time was optimal.
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The noise the chicks make in the hatcher is a good indication of how they feel. These are signals about the climate in the hatcher. Chicks that sleep and cheep softly are feeling comfortable. This indicates the correct climate. Chicks that make a lot of noise (screeching) are distressed and do not feel comfortable. They are too hot or short of breath. You can hear chick noise as soon as internal pipping has started. Behaviour and chick noise are good indications of how comfortable the chicks feel.
Pull time
Signals of timing the pull Pull time too late • • • •
> 5 meconium stained • eggs per basket All chicks are dry • Dry legs • Developed feathers
Pull time too soon Clean eggshells in the hatcher basket Some chicks still wet Viable chicks still in eggs
Here, the long feathers are already well developed. This indicates a late pull time. You should not be able to see the small, white feathers. If day-old-chicks are left too long in the hatcher, ‘white triangles’ protrude from the feather shafts. These dry legs indicate that pull time was too late. 140
Ha tc he ry S i gnal s
