Lohmann Hatchery Guide

22 LOHMANN TIERZUCHT › MANAGEMENT GUIDE 22 When the hatchery manager asks about perfect transfer time, many different op- tions and windows are opened up, which we would now like to clarify. The transfer process was standardised in the past at 444 hours, and is now set for all Multi-Stage incubators. In order tobalance the temperature and the air flow of the setter, all hatcheries work with this clear chronological order, including the trans- fer from setter tray to hatcher basket after 18.5 days. And in hatcheries that work with Single- Stage? There is a possibility of change at our exigencies, we don’t have to balance the setters of all our incubation machines, which can be empty from day 16 to 19, but is important to remember that at some point, the target at 18.5 is the perfect pa- rameter for the eggs’ weight loss data, the hatcher basket isn’t built for having the same air flow of the setter trays, and the majority of brands of hatcher have more cooling capacity, extreme air flow and ventilation. For this reason, in early trans- fer, we have to control and prepare a good programme which maintains in hatchers the setter condition from day 16 to day 18.5. The problem isn’t to stop turning but the anticipated transfer can cause some problems at hatch windows time and can reduce hatchability by around 0.5–1 %. At the same time a delayed transfer is possi- ble, if our hatch windows target is perfect- ly standard, but an excessive delay at day CANDLING AND TRANSFER 19.5 can dis- turb the embryos just starting with inter- nal cut, at this time eggs are more fragile and can be damaged from the automatic vacuum transfer machine. Incubation time is calculated from the mo- ment that our eggs reach the set-point, not from the effective switch-on of the in- cubator or from pre-heating start. For this reason we have to know the effective time that our machine needs for keeping eggs at the right temperature, and it is from this basis that our chronological time starts. A really important point is the climate of the room and condition of transfer, warm (25 °C – 28 °C) and in high hygiene and biosecurity, the basket that has to be washed and disinfected, totally dried and wormed, which process should be gentle and as short as possible. If an automatic machine is in use to keep this movement soft and stop it causing damage, and the hatcher machine is switched on and at the right temperature just at set-point, the hatcher programme, if present, should run in the perfect stage. If manually operated, the operator has to fix about the chrono- logical requirements. CANDLING AND TRANSFER Transfer