Dietary date (Phoenix dactylifera) modulates antioxidant defenses, immune function, and cecal microbiota to improve performance in Muscovy ducks.

Phytogenic feed additives from agro-industrial byproducts are increasingly explored as antibiotic alternatives in poultry, yet their efficacy in Muscovy ducks remains poorly documented. This study investigated the effects of dietary date (Phoenix dactylifera) fruit supplementation at 0% (control), 5% (D1), and 10% (D2) on growth performance, blood biochemistry, antioxidant status, immune function, meat quality, intestinal morphology, and cecal microbiota in Muscovy ducks over a 42-day feeding trial. Date fruit supplementation dose-dependently improved final body weight, average daily gain, and feed conversion ratio (p < 0.05) without affecting feed intake. Serum antioxidant capacity was markedly enhanced, with elevated T-SOD, GSH-Px, and T-AOC alongside reduced MDA in both treated groups (p < 0.05). Immunologically, date significantly increased IgA and IgG while decreasing TNF-α and IL-6 (p < 0.05). Intestinal histomorphometry revealed improved ileal villus height, width, and crypt depth (p < 0.05). Cecal microbiome analysis showed increased alpha diversity, phylum-level shifts favoring Bacillota and Actinomycetota, and genus-level enrichments correlated with enhanced performance and immunity. Meat quality remained largely unaffected, with only reduced leg muscle redness. Correlation analyses linked specific beneficial genera to improved antioxidant and immune indices. Collectively, these findings provide the first systematic evidence that 10% whole date fruit inclusion is a safe, effective functional additive for Muscovy ducks, enhancing productivity through antioxidant, immunomodulatory, and microbiome-modulating mechanisms and offering a sustainable nutritional strategy to reduce reliance on synthetic additives in duck production systems.