Influence of dietary vegetable oils supplementation on egg quality of laying hens

Abstract Egg albumin and yolk are rich in bioactive compounds, giving them diverse biological effects and functional characteristics. In the current study, a total of 140 ISA Brown laying hens divided randomly into five groups (n = 28 in each group) were used in duration of 52 weeks (from 20 to 71 weeks of age). Enhancing the diet of them to improve the chemical and lipid composition of their eggs is crucial. This research monitored changes in egg composition from hens fed with diet containing 1.5% different vegetable oils. The analyzed egg groups are described as follow: G1 – control, diet without additional of vegetable oil; G2 – diet containing 1.5% flaxseed oil; G3 – diet containing 1.5% sunflower oil; G4 – diet containing 1.5% soybean oil and G5 – diet containing 1.5% canola oil. No significant changes were observed in water content, crude protein, fat, ash, or nitrogen-free extract across all groups. However, significant differences were found in the lipid composition (fatty acids, sterols, and phospholipids) of the eggs, with the most notable changes occurring after incorporating flaxseed oil into the diet. High quantities of palmitic acid (30.08 – 32.30%) were observed, with the highest level found in the diet with 1.5% soybean oil. Similarly, oleic acid (42.03 – 49.13%) was present in high amounts, with the highest level found in the diet with 1.5% sunflower oil. The quantities of biologically active substances in egg yolk varied with different diets, with unsaponifiables ranging from 1.03 – 1.53%, total sterol content from 0.50 – 1.03%, and phospholipids from 0.97 – 2.07%. Cholesterol (4.73 – 10.22%) was the main sterol, while phosphatidylcholine (47.17 – 59.63%), phosphatidylethanolamine (19.60 – 24.60%), and phosphatidylinositol (8.83 – 16.33%) were the main components of phospholipids.