SPIDES (Short Periods of Incubation During Egg Storage) is a procedure of short warming cycles for eggs in storage. It improves hatchability after prolonged storage of eggs, especially with younger flocks. Usually the procedure is done during storage every 5-6 days in a specially designed machine.
A problem of the system is that the procedure takes quite long. The machine have to warm up to incubation temperature, 36-37oC, remain on that temperature for a period of 3 hours, and than cool down again, either to storage temperature or to a temperature below 25oC. This limits the use of the machine to once or maximum two times a day. If the procedure needs to be done every 5-6 days, the number of eggs in the production cycles often outnumbers the number of machines available.
However, there is no actual need for a slow warming or cooling cycle. Research and practical experience show that a fast cooling and a fast warming do not harm the embryos. Which of course is logical, as in nature mother hen has no option for slow cooling or warming as well. But if this is the case, it raises the question if we should not try to speed up the process, to allow the machines to be used more often. Most commercial SPIDES machine have separated warming and cooling systems. The eggs are brought in the machine and the process is started. The machine takes often 4 to 6 hours to warm to 36-37oC, than the temperature is kept at that level for 3 hours and the machine starts to cool.
If we first of all take out the eggs from the machine after that period of 3 hours at 36-37oCand place them in the normal egg storage, the eggs will cool down to the egg storage temperature. It will be important to use additional fans to bring air flow over the eggs, to let them cool down quickly but especially also uniformly. If there are other eggs in that room it is important that the energy of the cooling eggs will not significantly warm up the normal eggs in storage, so the air velocity direction has to be pointed away from the other eggs and there should be enough volume in air and eggs and enough cooling capacity in the egg storage room.
But if we take out the eggs directly after the so-called plateau phase in SPIDES, the period of a constant temperature for 3 hours of 36-37oC, we do not need the cooling system of the machines anymore. This means that instead of cold water, we can run warm water through the pipes instead. This will speed up the warming process of the machine significantly, resulting in a shorter period of warming and a shorter process. If we are able in that way to shorten the warming process by half, the total process will only take 3 hours of warming plus 3 hours of plateau, instead of 5-6 hours of warming, 3 hours of plateau phase and another 5-6 hours of cooling. So effectively we can expect that the process will be shortened by 50%, allowing us to use the machine two times more.