How genotype influences the egg quality in the second half of laying cycle?

• Published in: Journal of Central European Agriculture Vol. 21; no. 2; pp. 215 - 221
• Main Authors: Kraus, Adam, Zita, Lukáš, Krunt, Ondřej, Pokorná, Kamila
• Format: Journal Article Paper
• Language: English
• Published: Agronomski fakultet Zagreb 01.01.2020; University of Zagreb, Faculty of Agriculture
• Subjects: age; albumen; egg; eggshell; genotype; layer; technological value; yolk
• ISSN: 1332-9049; 1332-9049
• DOI: 10.5513/JCEA01/21.2.2683

The objective of this study was to determine and compare egg quality from two genotypes of brown egg-laying hens in the second half of laying cycle (from 46 to 74 weeks of age). Commercial hybrids Hisex Brown and Lohmann Brown Classic were used in this study. Both genotypes were kept in enriched cages. 1920 eggs were evaluated. The significant effect of genotype was found in all evaluated traits except for the eggshell proportion and reflectivity. Results show that eggs from Lohmann Brown Classic hens had a superior quality in majority of the evaluated traits. Higher values were observed in main egg quality traits, such as egg weight (by 1.45 g, P≤0.0001), eggshell strength (by 2.48 N*cm-2, P≤0.0005) and Haugh units (by 3.27, P≤0.0001). The significant effect of age was determined in all selected egg quality traits. The egg weight increased with the age, meanwhile other traits such as egg shape, albumen and yolk index, Haugh units and eggshell strength decreased. The trend of the rest of evaluated traits was ambiguous. Furthermore, the interactions between genotype and age were determined. Regarding the extension of laying cycle, further research is required, because the egg quality rapidly decreases with the age.