SPIDES

SPIDES

Effect of SPIDES on hatching results

If hatching eggs have to be stored for longer than 7 days, the eggs can be warmed to incubation temperature briefly and under controlled conditions. Hatching eggs vary in their developmental stage and this technique evens out the differences. This process is called heat treatment or SPIDES (Short Periods of Incubation During Egg Storage). The eggs are sometimes even heat treated several times, for example at hatcheries that produce layers or parent stock. In natural conditions, the hen lays an egg every day until her clutch is complete. Each time she sits on the nest and lays an egg, the older eggs in the nest will be warmed. So by regularly sitting on the nest she incubates the eggs for short periods. After laying, she leaves the nest until she is ready to lay the next egg. A fertilised embryo normally consists of about 40,000 cells. This number decreases the longer the egg is stored because the viability of the cells is reduced, and they even start to die. The SPIDES technique activates the cells and the number of viable cells increases again. This creates strong embryos that will still be able to achieve good hatchability, including better chick quality, even after a prolonged storage period. In a setter, the eggs are heated for a short period (3-4 hours) to a minimum of 32°C and a maximum of 38°C (90-100°F). As soon as they reach a temperature of 32°C, the eggs can be cooled back down and stored again. The eggs must not be heated for longer than 4 hours, otherwise the embryos will develop too far which leads to higher embryonic mortality. If multiple SPIDES treatment is given, do not heat the eggs to above 32°C for any longer than a cumulative time of 12 hours. In practice, this means heating for no more than 3 times for 4 hours at 4–5-day intervals. Some hatcheries have a separate incubator that allows a controlled SPIDES treatment according to a fixed program. Other hatcheries use the standard incubators, but use a special program. This technique is usually applied when the eggs arrive at the hatchery, because the schedule has already been finalised and, accordingly, how long the batch of eggs will have to be stored. Some incubator manufacturers include an option for SPIDES in the incubation program settings.

100 +2.5% +3.5% 90 { { +14.3% Hatch of all eggs set (%) 30 40 50 60 70 80 { 98.5% 86.7% 89.2% 83.5% 87.0% 62.6% 76.9% 20 10 0 Fresh Stored eggs 7 days Stored 7 days SPIDES Stored 14 days Stored 14 days SPIDES Stored 21 days Stored 21 days SPIDES The effect of SPIDES on hatchability of eggs stored for 7, 14 or 21 days This graph shows that the hatchability of eggs treated with SPIDES during storage is higher than the untreated eggs. Effect SPIDES-duration on hatchability 70 80 75 85 90 95 100 control 1 week 2 weeks % chicks from fertile eggs 3 hours 6 hours 9 hours control 3 hours 6 hours 9 hourscopyright protected A heating time of 3-4 hours is considered optimal. With a storage period of 1 week you can notice a peak at around 3 hours. However, with longer storage, a slightly longer SPIDES duration is optimal. Therefore, there is no fixed, optimal duration of SPIDES treatment. This is microscope image of a young embryo. Above cell development stage 14 (Hamburger-Hamiltonclassification); the incubation process must continue otherwise the embryos will die.