Journal of the Hellenic Veterinary Medical Society, cilt.75, sa.2, ss.7551-7562, 2024 (SCI-Expanded)
The effects of lutein (L) and zeaxanthin (Z) inclusion to standard or omega-3 fatty acids enriched laying hens’ diets, on performance, egg quality parameters, fatty acids and individual carotenoids of egg yolk were investigated. The dietary treatments were designed as: standard (S) diet, 50 mg/kg L plus 50 mg/kg Z (S+L/Z (50+50)) or 100 mg/kg lutein plus 100 mg/kg zeaxanthin (S+L/Z (100+100)) added to S diet, Omega-3 fatty acids enriched (OM3) diet, 50 mg/kg lutein plus 50 mg/kg zeaxanthin (OM3+L/Z (50+50)) or 100 mg/kg lutein plus 100 mg/kg zeaxanthin (OM3+L/Z (100+100)) added to OM3 diet. The study lasted for 5 weeks. Laying hens with a mean live weight of 1525.88 ± 31.19 g were divided into six treatment groups, each group had three replicates. During the experimental period, there was no mortality rate recorded. Dietary inclusion of L/Z (50+50 or 100+100) either in the S or OM3 diets did not alter performance parameters. Eggs from hens fed an enriched diet (OM3) significantly increased (P<0.05) the albumen index and Haugh unit (HU). Dietary inclusion of L/Z (50+50 or 100+100) in the S or OM diet significantly improved (P<0.05) total carotenoid, unknown carotenoid, lutein and zeaxanthin concentrations of egg yolk compared to the S or OM diets. The yolk color a* value was significantly increased by inclusion of L/Z (50+50 or 100+100) to diets (S or OM3) (P<0.05) and this was correlated with increased (P<0.05) concentration of individual carotenoids. The major changes in egg yolk fatty acid MUFA and PUFA composition occurred when laying hens were fed with OM3 or OM3+L/Z (50+50 or 100+100) diets.