No abstract

The aim was to assess the internal and external quality of consumer eggs of egg‑laying hens of two selected genotypes depending on their age. All of these hens were kept in enriched cages. There were compared eggs from Hy‑Line Brown and ISA Brown hens at the age from 36 to 64 weeks. In total, 3840 eggs from 300 hens were evaluated. Quality of eggs was determined by their technological value. Statistically significant interactions (P = 0.001) between age and genotype were found in all evaluated parameters except for the yolk colour (P = 0.044), whereas there was not found interaction (P = 0.072) between age and genotype in eggshell strength. The significant effect of hens’ age was found in all evaluated parameters, with the only exception of the yolk colour. The results showed that the average weight of eggs, eggshell, albumen and yolk increased with the age. Also the eggshell proportion, its colour and yolk index values ​​increased, whereas the egg shape index, eggshell thickness and strength, albumen proportion, Haugh units, the albumen and the yolk index decreased. Statistically significant effect of the genotype was found in all evaluated parameters except for the yolk index. When comparing both genotypes, the eggs from ISA Brown hens had a better quality. The trend of deteriorating egg quality with age was confirmed.

No abstract

No abstract

The present study compared the fatty acid profile and some physical parameters of eggs from hens reared according to the organic system at the beginning of the first and second laying cycle. A total of 1080 eggs were analysed at the beginning of the first (from the 28th to 30th week of age) and the second (from the 78th to 80th week of age) laying cycle. It was found that the hen ages influenced the egg weight, egg surface area, yolk proportion, and eggshell colour. Albumen and eggshell proportion, albumen, yolk index, Haugh unit score, and eggshell strength were lower in eggs from older hens compared with those produced from younger layers. Monounsaturated fatty acids were found in higher amounts than saturated fatty acids and polyunsaturated fatty acids in egg yolks of eggs from layers only at the beginning of the second laying cycle. The PUFAn-6/n-3 ratio, saturation, atherogenic, and thrombogenic indices were significantly lower in the egg yolks from older hens compared to younger layers. These findings (regarding the eggs from the older ones) prove that it is practical to utilize them in the organic farming system during a period of two years.