Effects of dietary Arthrospira platensis phycocyanin on growth, fatty acid assessment of breast muscles, hematobiochemical, immunological responses, and hepatic histomorphology in broiler chickens

Arthrospira platensis is used as a feed ingredient in humans, livestock, chicks, and fisheries. The objective of this study was to inspect the effectiveness of A. platensis phycocyanin on broiler chicken growth outcome, carcass features, fatty acid profiling in breast tissue muscles, blood biochemical profiles, immune response, hepatic histology, and immune expression of splenic immunoglobulin G (IgG). 500 three-day-old male broiler chicks were assigned to five experimental groups (average body weight 89 ± 0.32 g per chick) and consumed basal diets fortified with 5 levels of phycocyanin (0.00, 0.25, 0.50, 0.75, and 1.00 g kg⁻¹ diet) for thirty-five days. Different phycocyanin dosages had no impact on broiler growth outcomes, the yield of carcass percentages, or internal and immune-related organs compared to the phycocyanin 0.00 group (p > 0.05). Dietary phycocyanin significantly boosted the proportions of the total n-3 polyunsaturated fatty acids (PUFA), n-6 PUFA, and n-3/n-6 PUFA (p < 0.05) in chicken breast muscles at a concentration-dependent level. There was an increase in lysozyme, interleukin-10, and complements 3 serum levels. A significant rise in red blood cell count, hemoglobin content, white blood cells, and heterophils counts was observed in chickens fed 0.25 g phycocyanin kg⁻¹. No significant changes in blood alanine aminotransferase, aspartate aminotransferase, creatinine, or uric acid levels were seen in response to dietary phycocyanin. The phycocyanin-fed chicken groups had typical hepatic histomorphology like the control group. Moreover, the dietary phycocyanin doses of 0.25—1.00 g kg⁻¹ upregulated the immunohistochemical staining of IgG in the spleen. In conclusion, phycocyanin can be added to broiler chicken diets at concentrations of up to 1 g kg⁻¹ without adversely affecting growth. Phycocyanin supplementation enriched the breast musculature in n-3 and n-6 PUFA and boosted the birds’ immune response.