Lohmann Hatchery Guide

21 21 LOHMANN TIERZUCHT › MANAGEMENT GUIDE This method is humane and doesn’t destroy or damage the live embryos. It is important to have a representative number of eggs in the test (dirty or floor eggs don’t give a reliable average). › › Medium candling is carried out in some hatcheries at around day 10 of incubation, in special cases in the old- est flock with poor fertility. It is done in order to refill the tray with fertile eggs and to improve the uniformity of tem- perature during the setter process, to have more space following the incuba- tion, and also to reduce and speed up the transfer job. It is possible to use a “candling table” in dark room, although automatic candling machines that can carry out this process also exist. › › Transfer candling is the most com- mon method for every hatchery, as it isn’t necessarily an extra job. During the transfer operation from tray set- ter to hatcher basket, the eggs can be processed with a “candling table” or automatic machine, which can remove all the clear eggs and dead embryos. Extra attention must be paid when the percentage of removed eggs is over 15 %, as it is important to refill the hatcher basket. At the moment, only prototype machines for refilling exist, and in gen- eral this refilling process is done manu- ally. However, it is always necessary to heed the fragile condition of the eggs, so as to avoid damaging the embryos. The candling is important, because any clear eggs transferred to the hatcher don’t produce metabolic heat and therefore cre- ate an unstable climate. In situations with different flocks with different fertility rates in the same hatcher, this causes problems during hatching, from increases in hatch window time to the percentage of em- bryos which are piped but don’t hatch. All tests which have taken place confirm that chicks’ quality is improved through the candling of eggs, and that the number of chicks damaged during the chicks take-off is reduced. In conclusion, these are the reasons for candling: 1. Early detection of farm problems, male condition and general health and stor- age conditions; right S.P.I.D.E.S. use; cor- rect incubator conditions and manage- ment 2. Creation of a good collection of refer- ence data, to use with necropsy for identifying and resolving problems quickly, and to have a general view of the farm and the hatchery 3. Good estimation of the percentage of hatched chicks 4. Optimisation of space in setter (previous and middle candling) 5. Separation of waste into a different category of risk and reduction of costs (eggs to shell calcium); the possibility of selling unfertile eggs for use as animal food; reduction in terms of kilograms of waste in the hatchery per day 6. Improvement of quality of chicks; im- provement of performance; optimisa- tion of hatcher space and use