Tags: Egg handling | Whitepaper
27 August 2010,
Egg storage is the time between oviposition (laying) and the start of the incubation process for hatching eggs. Optimal hatching results and chick quality can be achieved if eggs are set after an initial adaptation period of about 1 to 2 day(s). This allows carbon dioxide to be released from the egg, which increases albumen pH from 7.6 at oviposition to pH8.8 - 9.3. Yolk pH remains virtually constant around pH6.5, so that the embryo, situated on the yolk, is exposed to a pH-gradient. This optimises early embryonic development.
Storing eggs beyond two days leads to loss of hatchability and reduced chick quality. An epidemiological study of Dutch hatchery data (Yassin et al. 2008) showed that, on average, each extra day of storage at the hatchery before the seventh day reduced hatchability by 0.2%, rising to 0.5% after the seventh day.
Day-old-chicks from stored eggs show a higher incidence of ‘black navels’. Tona et al. (2004) found that Cobb broiler chicks hatched from eggs stored for seven days weighed over 200 grams less at slaughter age, than chicks from fresh eggs. Differences in body weights emerged at 14 days post hatch and increased until slaughter age at 42 days.
In recent research by Pas Reform Academy, eggs from three different broiler breeder flocks of different maternal ages (30, 38 and 50 weeks) were stored at 18 - 20 ˚C and 12 - 14 ˚C for 7 and 11 days, both at 75% relative humidity. Storage at the lower temperature resulted in a higher average hatchability of 0.6% (experiment 1: 7 days), 1.1% (experiment 2: 7 days) and 3.2% (experiment 3: 11 days). These results support the view that ‘the longer the storage period, the lower the storage temperature’, but more research is needed before it can be concluded that suggested temperature ranges should change.
|Storage duration||Temperature (˚C)||Relative humidity (%)|
|0 - 3 days||18 - 21||75|
|4 - 7 days||15 - 17||75|
|8 - 10 days||10 - 12||80 - 88|
|More than 10 days||10 - 12||80 - 88|