Effect of Egg Weight on External and Internal Qualities, Physiological and Hatching Success of Japanese Quail Eggs (Coturnix coturnix japonica)

Abstract

This experiment was conducted to evaluate the effect of egg weight and egg physical characteristics on embryonic development, hatchability, and hatchling weight of Japanese quails (Coturnix coturnix japonica). In total, 689 eggs were classified in two categories: small (<13.5 g) or large (≥13.5 g), and different external eggshell and internal quality traits were measured. On days 6 and 14 of incubation, tissue triiodothyronine (T3) and thyroxine (T4) were extracted from embryos in both egg sizes and analyzed. Relative to internal egg-quality traits, large eggs had significantly higher yolk height, yolk diameter, yolk weight, albumen height, and albumen weight than small eggs (p≤0.01). However, Haugh unit score (p=0.27) was not significantly different between the two egg sizes. Relative to eggshell quality parameters, large eggs had significantly higher total pore count, surface area, eggshell volume, and eggshell weight than small eggs (p≤0.05), with consequent higher hatchability rate and hatchling weight. Pearson's correlation coefficients revealed significant correlations (p≤0.05) between egg weight and different external and internal egg quality parameters. Thyroid hormone levels were not significantly different between egg groups on d 6 day, while on d 14, a significant difference was recorded (p≤0.05). In conclusion, larger egg sizes are recommended to obtain better hatchability, lower embryonic death rates, and heavier hatchlings compared with smaller eggs of Japanese quails.

Correlation Between Egg Weight and Egg Characteristics in Japanese Quail

“…The physical qualities of quails' eggs play a very critical role in embryonic development. According to the finding of [9] Haugh unit was not influenced by egg size in quails. However, they reported of significant effect on larger eggs on yolk height, yolk diameter, yolk weight, albumen height and albumen weight than the small eggs.…”

Modelling conditions of storing quality commercial eggs

“…The average of the widest and the narrowest horizontal circumference was measured as the yolk diameter. Moreover, the standard of the broadest flat rim enclosed by the egg white was calculated as the albumen diameter as documented by Hegab and Hanafy (2019) ; Oleforuh-Okoleh and Eze (2016) , and Sola-Ojo et al. (2016) .…”

Analysis of quality and prediction of external and internal egg traits in Mexican native turkey hens

“…In other domestic poultry species such as chickens (Juárez-Caratachea et al, 2010), Guinea fowl (Nowaczewski et al, 2008), partridge (Alkan et al, 2015) and quail (El-Tarabany, 2016;Hegab and Hanafy 2019) it has also been reported that the weight of the egg has significant correlations with albumen weights, yolks and shell. The strong linear relationships between the egg traits mentioned above, imply that these traits are probably under the influence of the same genetic action (Fajemilehin, 2017).…”

“…Egg weight (EW) and shell weight (SW) were taken using an electronic scale (Medidata ® ) with an accuracy of 0.01 g. Polar (PD) and equatorial diameter (ED) of the egg were measured with a digital caliper (Mitutoyo ® , Mizonokuchi, Japan) with an accuracy of 0.01 mm. Egg shape index (SI) was calculated considering the mathematical formula described by Hegab and Hanafy (2019). Shell percentage (SP) was estimated through the SW and EW relationship SW / EW x 100 ratio (Juárez-Caratachea et al, 2011).…”

“…Subsequently, albumen weight (AW) was estimated from the following mathematical formula: AW = EW -(YW + SW). The Haugh units (HU) were calculated considering the suggested by Hegab and Hanafy (2019). Albumen percentage (AP) and yolk percentage (YP) were estimated by the relationship between the AW or YW and the EW (Juárez-Caratachea et al, 2011).…”