A Brief Review on Phytobiotics for Enhancing Broiler Health and Sustainability in Tropical Production Systems

The global ban on antibiotic growth promoters (AGPs) in poultry production has intensified the search for safe and sustainable alternatives. Phytobiotics, plant-derived compounds with bioactive properties, have emerged as promising candidates due to their antimicrobial, antioxidant, and immune-enhancing effects. This review evaluates the role of phytobiotics, particularly saponins, in improving growth performance, immunity, and welfare of broilers under tropical production conditions. Saponins sourced from Yucca schidigera, Quillaja saponaria, mango leaves, Moringa leaf meal, and tropical grasses such as Brachiaria decumbens enhance gut health by increasing villus height, reducing crypt depth, and improving nutrient absorption. Quantitative comparisons show that supplementation with Yucca schidigera at 100 to 200 mg/kg improves body weight gain by up to 10% and feed conversion ratio by 7.4%, while mango leaf saponins and Brachiaria decumbens provide additional benefits in oxidative stress reduction and heat resilience. Phytobiotics also improve immunity, with IgG levels rising by up to 20% and heterophil-to-lymphocyte ratios decreasing by 14.5%. A novel aspect of this review is the integration of telomere length as a biomarker of welfare, with supplementation maintaining relative telomere length increases of up to 12.5%, indicating reduced cellular stress and improved longevity. While phytobiotics are effective, dosage optimization is crucial to prevent adverse effects such as digestive upset or toxicity. This review highlights the potential of locally sourced phytobiotics to replace AGPs, supporting antibiotic-free poultry production in tropical environments and emphasizing the need for standardized formulations, field validation, and mechanistic studies to guide practical implementation.