Lohmann Hatchery Guide

8 LOHMANN TIERZUCHT › MANAGEMENT GUIDE 8 ing the eggs’ natural temperature. This means that eggs should not be warmed to more than 24  °C or cooled drastically, and that eggs have to dry quickly and in a clean and controlled area after immersion. Please verify the corrosiveness of the prod- uct in use; many chemical products can damage structure, floor, trolley and trays. The effective dosage changes the value of disinfections, and for this reason it is im- portant to monitor consumption and per- centage in use, as well as using a secure system of dispenser. A peristaltic pump is a good tool, but every different system needs a format control routine. It is important that the hatchery controls the real efficiency of the product in use with accurate analysis, using shell tam- pons “swab”, or by the simple use of Rodac Plates. The hatchery should then decide on the relative dosage, whether the type of product can be used and in which form, and the application desired. HANDLING HATCHING EGGS At the time of deposition, a fertile egg al- ready contains a small live embryo, which is made up of approximately 30,000– 55,000 cells. This is a living miracle and we have to preserve the vitality of these cells until the point of incubation. Please remember to avoid the instable tempera- ture of eggs and to use your knowledge of handling carefully. The developments of the embryo’s life start in the body of the hen approximately 24 hours before the egg is laid, when the follicle is ovulated and fecundated. In these hours cellular replication is working very quickly – especially considering that the internal temperature of the body of the hen is 41 °C. Now our goal is to stop the fast cellular replication while at the same time maintaining the best liveability and reduc- ing the cellular mortality as much as pos- sible. In the past we spoke of “physiological zero”, which was under 26 °C, but in reality this “zero” does not exist, as the replication and the mortality of embryo cells is still a concern. The temperature range between 26 °C and 37 °C is unbalanced and the ve- locity of cellular mortality is much higher than replication. If the conditions don’t stay within the right parameters, we experience the “early dead” of our embryos. This is why it is especially important in countries with a hot climate to have more frequent egg collections, reducing the percentage of blastoderm mortality (early dead -72 h). Ideally, eggs should be cooled down uni- formly and gradually from the hen’s body temperature to between 17 °C and 22 °C in 6–7 hours. Please check the table showing different opti- mal egg storage temperatures and humidities in consideration of the storage time, set from the arrival of eggs at the correct temperature. Humidity during storage is not as impor- tant as the temperature. In short and me- dium storage it doesn’t have an big influ- ence, however, it should be kept between 60 % and 75 %. In long storage, the correct value can help reduce the risk of extreme- ly high weight loss of eggs. Optimal egg storage condition For eggs that will be set in the first 4 days, it isn’t necessary to drop the temperature; the right value helps the albumen of eggs to reach the perfect pH and also helps to bring about the right weight loss of eggs, but in the special circumstance of a Sin- gle–Stage process, this isn’t easy to reach. In a layer hatchery, it is common to store eggs for up to 10 days. For this storage length the use of S.P.I.D.E.S (Short Period Incubation During Eggs Storage) is recom- mended. In a well-planned schedule this isn’t a complication for hatchery life, it just needs careful attention and management. If S.P.I.D.E.S isn’t possible, it is still impor- tant to have the correct temperature and to avoid the jumps (ups and downs) in temperature. For this reason, egg delivery trucks have to fix a set-point temperature at the farm storage room value and the operators in the hatchery have to send eggs into a storage room at the right tem- perature, in order to continue with the previous incubation schedule. It is important to remember that eggs Egg storage room: climate conditions