The effect of time of oviposition and age on egg weight, egg components weight and eggshell quality

The effect of age and collection time on egg composition and eggshell quality was studied in an experiment with Hisex Brown laying hens in three periods during a laying cycle (20-24, 38-42 and 56-60 weeks of age). Eggs were collected daily at 6:00, 10:00 and 14:00 h. At each age range, every two weeks (3 times per age range) eggs were collected for egg quality analyses (total 1486 eggs). Egg weight increased with hen's age and the heaviest eggs were collected at 6:00. The same trends were found in yolk weight. Albumen weight grew slower than yolk weight and the effect of oviposition time on albumen weight was ambiguous. Deviations in increase of yolk and albumen weight were expressed in significant interactions for yolk: albumen ratio. In addition, significant interactions of age and oviposition time for eggshell weight, index, thickness and colour were found. High correlations were determined between eggshell thickness and eggshell index (0.85), eggshell weight (0.75), eggshell strength and eggshell index (0.52).