Medycyna Wet. 64 (4), 417-420, 2008
Okruszek A., Książkiewicz J., Wołoszyn J., Biernat J., Haraf G., Orkusz A.
Effect of genotype on some egg quality parameters of ducks from different conservative flocks
The objective of the study was to compare the chemical composition and fatty acid profile of eggs of two-year-old light type ducks: Orpington (O1) and crossbreed ducks Khaki Campbell × Orpington (KhO) as well as Pekin type ducks . P9, A1 and A2 from conservative flocks, collected at the onset (the 6th week) of the second laying period. There were no significant differences in the water content (in egg whites and yolks), cholesterol content in yolk lipids and pH value of egg whites in the investigated eggs. The eggs of A1, A2 and P9 contained more (P ≤ 0.05; 0.01) protein in egg white (11.01%, 10.97% and 10.85% respectively) and yolk (16.34%, 16.26% and 16.24% respectively) than O1 and KhO eggs (10.74% and 16.07% as well as 10.66% and 16.21% respectively). Furthermore the A2 eggs were characterized by the lowest of lipid contents in yolk (27.19% v/s 29.45-30.99%) and pH yolk value (6.27 v/s 6.31-6.40). In P9, A1 and A2 eggs, yolk lipids contained more C 16:0, C 20:5 ω-3 (EPA), C 22:4 ω -6 and C 22:6 ω -3 (DHA) and less CLA 18:2 ω -6 and trans isomer fatty acids (C 16:1 trans-9 and C 18:1 trans-11) than those of O1 and KhO eggs. The unsaturated fatty acids (UFA) were predominant in yolk lipids of eggs for all flocks (69.02%-72.28%). The A1 yolk lipids contained the most UFA, PUFA (19.74%) and SFA (27.41%). A higher concentration of PUFA from ù-6 group was observed in A1 (15.42%) and KhO (15.32%) eggs. Egg yolks collected from P9, A1 and A2 ducks were characterized by a higher level of ω -3 PUFA fatty acids (4.34%, 4.32% and 4.71% respectively) in comparison to KhO and O1 eggs (3.97% and 4.10% respectively). The more favorable ratio of ω -6/ ω -3 PUFA was counted for KhO (3.86) and A1 (3.57) eggs, but for the investigated flocks it was close to the recommended values of human diets.
Keywords: duck, conservative flock, egg, chemical composition, fatty acid profile