Effect of housing system on egg quality and the concentration of cholesterol in egg yolk and blood of hens of native resources of the Czech Republic and Slovakia

SUMMARY The effect of the housing system on egg production, quality, and the concentration of egg yolk and blood serum cholesterol was studied in hens from the genetic resources available in the Czech Republic and Slovakia. A total of 132 pullets was divided according to breed (Czech hens x Oravka hens) and the housing system (36 hens per enriched cage and 30 hens per litter). The eggs for the laboratory evaluation were collected over 2 consecutive d during 4-week periods. Significant interactions between breed and housing system were found in some egg quality parameters (with the exception of egg weight). Higher albumen and yolk quality were found in Oravka hens on litter, but higher eggshell quality was detected in Czech hens on litter. The cholesterol concentration in egg yolk was significantly affected by the breed and housing system of hens. A significantly higher average concentration of cholesterol in egg yolk was in Oravka hens (11.22 mg/g) and in layers housed on litter (11.24 mg/g). The influence of the housing system and interaction between the breed and housing system on cholesterol concentration in blood serum were significantly different. The highest concentration of cholesterol in blood serum was in Oravka hens in cages (3.65 mmol/l). The results show that the selection of a suitable genotype and housing system can affect egg quality and the concentration of cholesterol in egg yolk.