Shell temperature: How shall we tell if a still gosling is under the eggshell?

• Published in: Theriogenology 2024-09, Vol.226, p.57-67
• Main Authors: Narushin, Valeriy G., Romanov, Michael N., Gressier, Louis, Jacob, Elouann, Salamon, Attila, Klein, Sabine, Kent, John P.
• Format: Article
• Language: English
• Subjects: Animals; Egg cooling rate; Egg Shell - physiology; Geese - embryology; Geese - physiology; Goose eggs; Hatchability; Models, Biological; Non-destructive testing; Ovum - physiology; Shell temperature; Specific temperature index; Temperature
• ISSN: 0093-691X; 1879-3231; 1879-3231
• DOI: 10.1016/j.theriogenology.2024.05.045

The present investigation was aimed at predicting a still (i.e., dead) vs. live embryo within a hatching goose egg by measuring the eggshell cooling rate. For this, we daily measured the temperature (T) values on the shell surface of goose eggs after they were removed from the incubator and during further natural cooling. T was recorded every 0.5 h for further 1.5 h of cooling. It was possible to recognize eggs with dead embryos using the combination of T, egg weight (W), and surface area (S). The resultant indicator (TS/W) was called specific temperature index (STI). The mathematical relationship using STI measurements between Days 8–13 facilitated 80 % correct identification of the eggs with dead embryos. Additionally, we derived mathematical dependencies for shell weight (Ws) and thickness (t) by utilizing the values of W, egg volume (V), S, the average T of all measurements taken, as well as the drop in T during 1.5 h of natural cooling. The key advantage of these parameters was their measurement and/or calculation by applying non-destructive methods. The integrated application of these parameters resulted in achieving high calculation accuracy as judged by correlation coefficients of 0.908 for Ws and 0.593 for t. These novel mathematical models have the potential to decrease hatching waste by predicting embryo viability. Our research will add to a toolkit for non-invasive egg assessment that is useful in the poultry industry, research on eggs, and engineering. [Display omitted] •We aimed at predicting still (dead) vs. live embryos in goose eggs by cooling rate.•We measured shell surface temperature (T) during natural cooling for 1.5 h.•Specific temperature index was derived to predict correct identification of eggs.•We propose this index to predict eggs with dead embryos and reduce hatching waste.