This study evaluated the effects of dietary Spirulina ( Arthrospira platensis ) powder supplementation on production performance, egg quality traits, systemic antioxidant capacity, and selected blood immune–endocrine biomarkers. Two hundred 50‑week‑old Hy‑Line W‑36 laying hens were randomly assigned to four treatments for a period of 8 weeks (5 replicates per treatment, 10 hens per replicate). The treatments included a basal corn–soybean meal diet (control) or the basal diet supplemented with Spirulina at 1,000, 3,000, or 5,000 mg/kg, replacing an equivalent amount of corn starch. Dietary Spirulina improved productive efficiency in a predominantly linear manner, increasing egg production and egg mass while reducing feed intake and feed conversion ratio. Egg internal quality was enhanced, as evidenced by higher Haugh unit and albumen height, alongside modest changes in relative component weights and increased shell thickness. Antioxidant defenses were strengthened, with higher activities/concentrations of key antioxidant enzymes and glutathione, concurrent with lower malondialdehyde concentrations, indicating reduced lipid peroxidation. Moreover, Spirulina supplementation favorably modulated blood profile indices linked to protein status and humoral/innate immunity (e.g., total protein, albumin, immunoglobulins, complement component 3, interleukin-10, and lysozyme). Thyroid-related indices (T3 and T4) also increased, suggesting potential metabolic support consistent with improved performance. Overall, these findings demonstrate that dietary Spirulina powder elicits beneficial, largely dose-dependent improvements in laying performance, egg quality, antioxidant status, and immune-related blood traits, with the highest tested level (5000 mg/kg) generally producing the greatest responses.
Yousefi et al. (2026) studied this question.