Dataset on quality parameters of fertilized eggs stored for one week at 12 °C and 80% relative humidity, with or without 2% CO₂, and after a 24-hour acclimatization at 20 °C

In hatcheries, hatching eggs are commonly stored before incubation in order to facilitate the synchronization of hatchings and to meet customer demand for chicks. Recommendations for long storage (>15 days) is to store egg at temperature ≤12 °C, 80 % relative humidity to maintain internal egg quality without affecting embryo viability. In this data paper, we provide data related to the evolution of quality parameters of hatching eggs from the day of lay up to seven days of storage at 12 °C, 80 % relative humidity, with or without 2 % CO₂. Several egg quality parameters including albumen pH, Haugh units, yolk index and color, eggshell breaking strength, and percentage of eggshell. The distribution of eggs by batch, the description of quality parameters and their raw values are available as excel files (Research Data Gouv repository). The quality parameters of eggs (<i>n</i> = 15 per condition) were measured on the day of lay, and after one, three, five, six, and seven days of storage. The article also includes a comparison of the quality of eggs stored for six days with or without a 24-hour thermal acclimatization. Statistical analysis (Kruskal-Wallis followed by Dunn tests for multiple comparisons, <i>p</i> < 0.05) showed that the overall quality of albumen was higher for eggs stored under CO₂ conditions compared to control eggs (higher Haugh units, lower pH). These values were not significantly different from those from eggs analyzed on the day of lay. While the pH of eggs stored at 12 °C and 80 % relative humidity (control conditions) gradually increased over storage, the pH of eggs stored in the same thermal conditions than controls but with 2 % CO₂ remained stable throughout the storage period. Haugh units were significantly lower in eggs stored under control conditions from day three of storage onwards compared with 2 % CO₂ eggs and unstored eggs (freshly laid eggs). Regardless of the condition, eggs exhibited a loss in egg weight during storage with no significant difference observed between conditions. None of the other parameters (yolk index and color, eggshell strength and thickness) showed any statistically significant differences between groups. Furthermore, the statistical analysis showed that a 24-hour thermal acclimatization induced a higher loss of egg weight than in eggs stored for six and seven days under control or under 2 % CO₂. None of the other parameters was affected when comparing values of acclimated eggs to those of the eggs stored under control conditions or under 2 % CO₂ for six or seven days. These data can be reused as a reference to optimize the storage conditions of fertilized eggs from chicken layer breeds, in order to maintain egg quality during storage and improve the viability of chicken embryos and their hatchability. It also highlights the effect of thermal acclimatization for 24 h on the internal quality of eggs.