ABSTRACT
Background and Aim: Okra (Abelmoschus esculentus) contains bioactive compounds with potential applications as poultry feed additives. However, differences in plant parts, processing methods, inclusion levels, and experimental conditions have produced inconsistent findings. This systematic review evaluated the effects of dietary okra supplementation on poultry growth performance, intestinal health, metabolic responses, and product quality, and assessed the certainty of the available evidence.
Materials and Methods: The review followed the Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidelines and was retrospectively registered on the Open Science Framework. Scopus, Web of Science, PubMed, and AGRIS were searched through October 2, 2026, supplemented by citation tracking and regional-journal searches. Controlled poultry feeding trials were evaluated using an adapted Systematic Review Centre for Laboratory Animal Experimentation risk-of-bias tool. Standardized mean differences were calculated using Hedges' g. Because studies lacked sufficient comparability for meta-analysis, findings were synthesized narratively following the Synthesis Without Meta-analysis guideline. Evidence certainty was assessed using the Grading of Recommendations Assessment, Development and Evaluation framework adapted for animal studies.
Results: Thirteen controlled studies comprising 15 reports were included: ten involving broilers, two involving laying hens, and one involving turkey breeders. Eight studies were judged at high risk of bias. Low-dose seed and fruit powders generally showed favorable growth responses, with positive body weight estimates in eight of 11 treatment arms. Significant standardized effects were observed with 1 g/kg dried fruit powder (g = 1.38) and 1% seed powder (g = 2.44). Feed conversion improved with 1%–2% seed powder, although the evidence was inconsistent across preparations. Okra meals and processing wastes did not consistently improve growth performance, and several reports contained discrepancies in dietary formulations or duplicated performance data. Limited studies reported changes in intestinal bacterial counts, villus morphology, serum biochemical indicators, antioxidant responses, meat oxidation, and pigmentation. Evidence certainty was low for growth, feed conversion, intestinal outcomes, and meat quality, and very low for other outcomes.
Conclusion: Dietary okra effects depend on plant part, processing, and inclusion level. Low-dose seed and fruit powders show potential for improving broiler performance, whereas high-inclusion meals and wastes lack consistent benefits. Current evidence does not support a definitive optimal dose. Standardized, adequately replicated feeding trials are required before routine supplementation can be recommended.