By using heat treatment during storage up to 14 days, as part of your standard hatchery practice, it is possible to gain up to 6 to 7% in turkey egg performance. Standard programs have been developed to advance the development of embryos to a more robust stage.
Regaining up to 60% of performance that would have been lost due to storage
Heat treatment of stored eggs has been around for a long time and has many names: SPIDES (Short Periods of Incubation During Egg Storage) or PRESI (pre-storage incubation) or IDEAS for example. However, the results have previously been variable and the process had not been widely accepted by the industry. The Petersime Re-Store machine uses specially adapted technology to control the heat treatment program. It thereby uses the shell temperature of the eggs. Not only to control the air temperature of the machine, but also to control the timing of the steps in the program itself. The ‘special’ steps only change when the eggs tell the machine it is the correct time to change. Using this technology means that every egg gets the same treatment, producing a previously unobtainable consistency in results.
Performance losses increase as storage time increases. Eggs stored for 1 to 7 days are considered fresh eggs and have small losses due to storage time, whereas eggs stored for longer than 7 days can see significant losses. As a rough guide, it is possible to gain back up to 60% of the performance that would have been lost due to the effect of storage.
Most robust developmental stage
Because turkey production is more seasonal than chicken and flocks tend to be smaller, turkey eggs tend to be stored longer than chicken eggs and therefore have the potential to gain more from the use of Re-Store. The Re-Store process is used to advance the morphological development of avian embryos from the embryonic state at point of lay to a more robust developmental stage. By doing so, storage of eggs has the least detrimental effect on incubation performance.
The morphological development stages of eggs are often referred to by a scale known as EG&K or H&H. This is from a paper written by Eyal-Giladi & Kochav (EG&K) in 1976, where they describe the difference in the embryonic development prior to point-of-lay, and from a second paper by Hamburger & Hamilton (H&H) who describe the stages after point-of-lay.
Turkey eggs are at stage 7 or 8 (EG&K scale) at point-of-lay. As long as the collection, storage on farm, transport to the hatchery and egg storage room conditions are correctly managed, they will still be at stage 7 or 8 EG&K when set in an incubator. There is nothing wrong with setting eggs at morphological stage 7 or 8 EG&K. As long as they are fresh eggs there will be no loss in performance. But the most robust development stage for storage of eggs is when they are stage 13 EG&K. This means that if the eggs are stored at stage 13 EG&K, then they will lose the least amount of hatching performance.
Development of standard automatic programs
To investigate if turkey eggs indeed benefit more from heat treatment during storage, a cooperation was agreed with Le Helloco in France in a joint trial that Re-Stored over 3 million B.U.T. Premium eggs. A series of staging investigations were undertaken to firstly confirm that the eggs used for testing were at stage 7/8 and that the historical scientific information was still correct. Second, standard automatic heat treatment programs were established to advance the development of embryos to the more robust stage and the results were measured at Le Helloco.
Re-Stored eggs outperform untreated eggs by 6-7%
Once the standard automatic Re-Store programs were established, Le Helloco continued to use Re-Store and record the differences between treated and non-treated eggs over the 2015 – 2016 period. “When we first decided to start a trial of the Re-Store machine together with Petersime, we wanted to see if we could put the theory of SPIDES into practice in a real hatchery. We were lucky that we could collaborate with a team of experts from Petersime. Our expectations that pre-heating the eggs could help us to improve the quality of our turkey poults was soon confirmed,” says Mme Estelle Tanguy-Le Helloco, CEO of Le Helloco.
During the trials it was discovered that to achieve consistent results a number of rules have to be followed:
- The total time for Re-Store treatment for turkey is around 20 hours. It will depend on egg size, cold store temperature and egg temperature at removal.
- To ensure a uniform treatment, the eggs are heated to a specific shell temperature and held at that point.
- Too much time above 32°C will take development beyond ‘the point of no return’. Then the eggs will need to be incubated to the point of hatching, not returned to the cold store.
- Eggs must be returned to the cold store to ‘rest’ for minimum 24 hours after treatment before setting.
- Always try to fully load the machine to ensure an even airflow and homogenous environment. The idea is to give all eggs exactly the same treatment.
- The software and hardware have been modified for Re-Store and OvoScan™, so they do not work in the same way as in a standard setter.
- To achieve optimum consistent results, you have to optimize farm conditions, transport and hatchery procedures. Re-Store can only take development further, not backwards.
References are available on request.