LIPID PEROXIDATION, ANTIOXIDANT ENZYMES ACTIVITY AND GLUTATHIONE LEVEL IN EGGS FROM HERITAGE BREED AND COMMERCIAL CROSSES HENS

The objective of the study was to determine the activity of antioxidant enzymes and the level of GSH and MDA in yolk and white (albumen) of eggs. The experiment was carried out with 180 hens of three heritage breeds (Yellowleg Partridge, Sussex, Leghorn) and 180 commercial crosses of laying hens (Hy-Line, ISA Brown, Lohmann). Layers were reared in the litter system and had no outdoor access. Birds were assigned to groups I to VI (Yellowleg Partridge, Sussex, Leghorn, and commercial layers Hy-Line, ISA Brown and Lohmann, respectively). Birds were fed ad libitum standard diets based on concentrates for laying hens and had free access to water throughout the experiment. All the groups were managed under uniform environmental (air humidity and temperature, lighting programme) and feeding conditions. At 48 weeks of age, 6 eggs from each group were collected. In the samples of egg yolks and albumens the concentration of GSH and MDA, and activity of SOD, GPx and CAT were estimated. The results were statistically analysed by one-way analysis of variance and significant differences were estimated with Duncan's multiple range test. The egg yolks and egg albumens showed a statistically significant differences in the activity of SOD and GSH and MDA levels. The highest activity of SOD and the lowest level of MDA and GSH were observed in eggs from Sussex hens (of heritage breeds) and in eggs from Hy-Line (of commercial crosses hens). It is concluded from the present results that the origin of laying hens has an impact on the activity of antioxidant enzymes and GSH and MDA levels in eggs, which may affect their quality.