Twenty eggs from each dietary treatment (5 eggs per replicate group) were taken randomly to determine exterior (eggshell thickness, shell breaking strength) and interior (Haugh units, egg yolk color) egg quality.
Egg samples were stored for 24 h at room temperature, and then measurements were performed.
Each egg was initially weighed using an Egg Analyzer (ORKA Food Technology Ltd., Ramat Hasharon, Israel).
Then, the egg was broken, and the egg’s contents (albumin and yolk) were placed on the measuring tray of the Egg Analyzer for the determination of albumen height, Haugh unit number and yolk color.
Haugh units were automatically calculated within the system based on the values entered for egg
weight and albumen height.
Eggshell thickness was a mean of measurements taken at three locations on the egg (air cell, equator, and sharp end) with an Egg Shell Thickness Gauge (ESTG-1, ORKA Food Technology Ltd.,
Ramat Hasharon, Israel).
Eggshell breaking strength was measured by a cantilever system by applying increased pressure by force gauge (Imadas , Newton) to the broad pole of the shell (Balnave and Muheereza, 1997).