Lohmann Hatchery Guide

19 19 LOHMANN TIERZUCHT › MANAGEMENT GUIDE Ventilation is very important for our em- bryos: we would like to share this argu- ment in two parts 1. The correct ventilation in terms of air flow. 2. The correct provision of oxygen and the right conditions for the weight loss of eggs. N°1 In Multi-Stage setters it is very important to always have, the maximum of air flow power for all trays setting, in order to guarantee the same treatment of all differ- ent eggs of various ages. In Single-Stage machines the air flow is veryimportant at the start of the setter process, to guaran- tee uniformity of temperature and short warm-up. These are positive points and they reduce the rate of very early embry- onic mortality. However, when they reach the set-point in the first 4/5 hours up until day 12/14 of the process, our eggs don’t need extreme air flow; the production of warmth of our embryos is very limited, and if the machine has the possibility of safe energy, we take this opportunity. The requirement changes in the last week of incubation are a guarantee of good air flow, good embryonic temperature, per- formance, and a reduction in hatch win- dows time. N°2 Damper/Valve action has to guarantee the correct provision of oxygen, every time. It is important to control our machine in this phase, and as every different setter has its own plan and system of works, it is crucial to remember some basic important points in first 7/9 days. Carbon dioxide (CO2) can help the embryos at the start and help to improve the blood vessels and the size, but after 11 days, CO2 is a poisonous gas which can increase mortality in chicks. The drive of valves with a CO2 sensor is a very useful tool in the situation of a partial- ly empty setter, or with a low fertility flock. Recommended CO2 value Time ppm % Multi-Stage incubation 2,700 0.27 All incubation process time Single-Stage 7,000– 10,000 0.7–1 Start to 9 days max Single-Stage 2,700– 4,000 0.27– 0.40 9–19 days It is important to remember that both situ- ations can influence the attainment of the right weight loss of eggs for the age, in or- der to have a correct fix point for a good hatcher performance. It is very important to replicate the natural action of a hen, in order to guarantee the correct eggshell temperature, to make sure that air flow has only one line of direction, and to change the position of eggs. The ob- jective is to: › › Resolve adhesion of embryo to the shell membrane › › Correct development of air cell position › › Improve development of vascular area, which helps yolk condition and relative use from chicks › › Allow normal transfer of albumen pro- teins in amniotic fluid › › Improve the blood vessels under the shell, to maximise oxygen absorption › › Avoid the lower growth of embryos shown in unturned eggs › › Help the embryos to reach the normal correct hatching position › › Reduce malposition and reduce the number of unhatched eggs The turning has to take place every hour. Some brands may have the possibility to change the frequency or to leave the eggs for some minutes in the plane position. This is a good resource and can be advantageous. It is important for the eggs to have an an- gle of 43°–45° and for them to be turned in the correct asymmetric movement. Turn- ing has to be slow and gentle and without any “catapulting” actions. It is very impor- tant that hatchery takes care and organ- ises routine control of actions and angles, because a malfunction can completely destroy the hatching performance. Turning isn’t necessary after day 15 of in- cubation. For this reason, if the cooling ca- pacity of our machine isn’t sufficient, the Ventilation Turning