Dietary polysaccharides extract from <i>Spirulina platensis</i> : a natural alternative for enhancing broiler performance and antioxidation status

1. The demand for natural alternatives to antibiotic growth promoters in poultry has led to growing interest in bioactive compounds, such as polysaccharides derived from algae. This study evaluated the effects of algae (<i>Spirulina platensis</i>)-derived polysaccharides (ADP) on growth performance, blood profiles, carcase characteristics, meat quality, amino acid composition and antioxidant status in broilers.2. A total of 320, 1-d-old Ross 308 mixed-sex broilers were randomly allocated to one of the five dietary treatments; a control diet (0% ADP) and diets supplemented with 0.15%, 0.30%, 0.45% and 0.60% of ADP. Each treatment included four replicates containing 16 birds each. The feeding trial was conducted over 42 d and was divided into three phases, including starter (1-14 d), grower (15-28 d) and finisher (29-42 d).3. Dietary inclusion of ADP at 0.30% significantly improved body weight gain and feed conversion ratio during the finisher (1.77 kg and 1.71, respectively) and overall (2.82 kg and 1.56, respectively) periods. There were no adverse effects observed on haematological, serum biochemistry or carcase characteristics.4. Supplementation with 0.45-0.60% ADP reduced cooking loss to 34-40% and improved meat cohesiveness by about 5%. Its inclusion elevated the levels of key amino acids, such as threonine, histidine, isoleucine, arginine and glutamic acid in the breast muscle. Additionally, ADP linearly increased hepatic antioxidant enzyme activities, including total superoxide dismutase (317.60-337.12 U/mg protein), glutathione peroxidase (39.98-48.70 U/mg protein), catalase (7.09-7.71 U/mg protein) and decreased malondialdehyde concentrations (0.63-0.68 nmol/mg protein) demonstrating enhanced oxidative status. These improvements were attributed to the prebiotic and antioxidant properties of <i>Spirulina</i>-derived polysaccharides, which enhance nutrient utilisation, maintain gut integrity and strengthen redox balance.5. This study provides preliminary evidence that polysaccharides derived from <i>S. platensis</i>, particularly at 0.30-0.45%, can be used as safe and effective feed additives in broiler diets. These compounds have the potential to enhance performance, oxidative stability and certain aspects of meat quality without adverse effects.