Phloretin as a functional feed bioactive in livestock: Biological role, biosynthesis, and practical applications

Phloretin is a natural dihydrochalcone polyphenolic compound predominantly found in apples and other plants, recognized for its broad bioactivities. Despite extensive investigation of its pharmacological effects in biomedical research, the functional roles and mechanisms of phloretin in livestock production remain limited. This article summarizes current evidence on the biological functions of phloretin in livestock nutrition and elucidates its underlying mechanisms of action and biosynthesis strategies. It provides a narrative review of published studies on phloretin across multiple databases. Phloretin exerts antioxidant and anti-inflammatory effects primarily through modulation of the key cellular signaling pathways, including inhibition of the nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) inflammatory pathway, activation of the nuclear factor erythroid 2-related factor 2 (Nrf2) antioxidant response, and regulation of glucose and lipid metabolism via AMP-activated protein kinase (AMPK) related signaling. These mechanisms contribute to improved intestinal barrier integrity, mitigation of lipopolysaccharide-induced oxidative stress, supporting overall animal resilience to environmental and metabolic stressors, and potential improvements in growth performance and reproductive function in livestock. These effects make phloretin a promising candidate for dietary supplementation in animal husbandry. Despite these promising findings, current research remains fragmented and largely limited to in vitro or non-livestock models, with insufficient data regarding optimal dosage and direct association with economically important production traits. Therefore, future studies integrating nutrigenomics and controlled feeding trials are required to understand the mechanistic links between phloretin supplementation, association with economic traits, health benefits, and dose determination. Hence, this article emphasizes the prospective use of phloretin as a functional feed additive and provides a framework for future research aimed at developing evidence-based applications in livestock production.