Effects of Dietary Antioxidant Supplementation on Productive Performance, Egg Quality, Immune Response, and Antioxidant Status of Laying Hens

الملخص

This experiment was conducted to reveal the effects of dietary antioxidants on the productive performance, egg quality, immune response, and antioxidant status of laying hens. A total of 120, 45-week old Hy-Line Brown hens, were randomly allocated using a random number generator to four dietary treatments for 10 weeks: T1=control (basal diet), T2(PE300) =basal diet + 300 mg/kg of phytogenic extracts blend, T3(VE100) = basal diet + 100 mg/kg of vitamin E, and T4 (SP1)= basal diet + 1 g/kg of Spirulina platensis. Each treatment had 6 replicate cages with 5 hens per cage (n = 6 replicates/treatment); the cage was the experimental unit. Data were analyzed using a linear mixed-effects model with treatment, week, and treatment × week as fixed effects and cage within treatment as a random effect. All treatments improved laying rate (4.7–7.6% relative to control), egg mass, and the calculated feed conversion ratio compared to control (P < 0.05). The Spirulina platensis group had a a significant increase in yolk color (P < 0.01). Serum IgY and IgA were increased by the dietary antioxidants, with a decrease in the pro-inflammatory cytokines, IL-1β and TNF-α (P < 0.05). However, VE100 did not significantly increase IgA relative to the control. Increased serum superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) activities with decreased serum malondialdehyde (MDA) was shown in the treated hens (P < 0.01).The lower IL-1β and TNF-α concentrations indicate a reduced pro-inflammatory status, not the presence of an inflammatory response. Data from this study suggest that dietary antioxidants given in the proper range improve productivity and immune response of laying hens.