Growth performance and physiological status evaluation of Spirulina platensis algae supplementation in broiler chicken diet

Spirulina platensis algae (SPA) is a natural feed supplement with 40 to 45% crude protein, 2.44% Ca, and 6.27% P. It contains substances (e.g., beta-carotene and zeaxanthin, and high Fe, vitamins and phycocyanin). These substances reveal potential biological properties such as antioxidative, anti-inflammatory, and hypolipidemic contain. The effects of dietary supplementation of SPA on growth performance, antioxidative, immune status, and intestinal histology were investigated. A total of 540 broiler chickens were randomly assigned into 3 treatments of 18 breeding pens each housed in 6 replicates per each experimental treatment (30 broiler chickens per pen). Three diets were formulated to contain 0, 3, and 6% of SPA and fed from d 7 to 35. Body weight and body weight gain at 5 wk of age were greater in the diet containing 6% SPA compared with the 0% SPA. The supplementation of SPA to a broiler chicken diet improved the feed conversion ratio. The obtained results of the experiment showed that broiler chicken fed with 3 and 6% of feed SPA increased RBC, Hb, and WBC and lymphocyte was greater (P <= 0.05) values compared to the 0% SPA. Serum total lipid, cholesterol, and triglyceride concentrations in the diet containing 3 or 6% SPA decreased compared with the 0% SPA. Furthermore, the concentration of high-density lipoprotein was increased, while the opposite is observed with low-density lipoprotein concentration. Serum Ca and P concentrations had greater in the diet containing 3 or 6% SPA compared to the 0% SPA. Both the 3 and 6% SPA groups increased (P <= 0.05) blood glutathione; however, the SPA groups decreased (P <= 0.05) malondialdehyde but increased blood immunity status relative to the control group. Moreover, the content of Ca and P in tibia ash increased in both broiler chicken fed the diets containing 3 and 6% SPA compared with those fed the diet containing 0% SPA. In comparison to the control treatment, all experimental chickens had increased villus height, goblet cells per 100 enterocytes and villus height per crypt depth in the jejunum histology examination. The inclusion of SPA in broiler chicken fed the diet containing of 6% had a considerably positive effect on growth performance and gut health status. In addition, it is a good source of Ca and P to increase tibia strength.