Effect of layer diets enriched in Omega-3 fatty acids supplemented with Cu on the nutritive value of the eggs

A trial on 120 Lohmann Brown laying hens (aged 60 weeks) was conducted for a period of six
weeks. The layers were assigned to 4 groups and housed in cages (2 hens/cage) on three tiers. Compared
to the diet for the control group (C), the diet for the experimental groups (E1, E2, E3) included 5% flaxseed
meal and 2% camelina meal. Compared to the Cu concentration in diet C (6 mg/kg), the diets for the
experimental groups contained: 75 mg Cu/kg (E1), 100 mg Cu/kg (E2) and 150 mg Cu/kg (E3) from
CuSO4x5H2O. Throughout the experiment the production parameters were monitored. Every two weeks,
18 eggs/group were collected for yolk fatty acids and cholesterol determinations. In the same weeks, 15
samples of excreta/ group, were collected which were assayed for Cu and Zn concentration. The use of the
experimental diets produced eggs with properties of functional foods because the yolk concentration ofα
linolenic acid was 75.56% higher than in group C, while the cholesterol concentration was significantly
(P≤0.05) lower than in group C. The 150 ppm Cu supplement (E3) produced the highest allowed load of
heavy metals in the droppings according to the acting norms for environmental protection.