Dietary mangosteen polyphenols and rosmarinic acid supplementation improves production performance and alleviates oviduct inflammation in LPS challenged laying hens.

This study aimed to investigate the effects of dietary plant polyphenols on laying performance, egg quality and oviduct inflammatory responses in laying hens challenged with LPS. A total of 192 Hy-Line Gray hens (55 weeks old) were randomly assigned to two dietary treatments for 8 weeks: a control group (CON, basal diet) and a plant polyphenols group (PP, 200 mg/kg mangosteen polyphenols + 200 mg/kg rosmarinic acid), with 8 replicates of 12 birds each. After 8 weeks, sixteen hens per group were selected and allocated to lipopolysaccharide (LPS) challenged and no challenged groups, forming a 2 × 2 factorial arrangement with four treatments and 4 replicates of 2 birds each. During the feeding phase, PP supplementation significantly reduced feed conversion ratio (FCR) and serum alkaline phosphatase (ALP) activity (P < 0.05). During the challenge phase, there were significantly increased serum concentrations of the pro-inflammatory cytokines interleukin-1β (IL-1β), interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α), along with markedly elevated levels of IL-1β, IL-6, TNF-α and interferon-γ (IFN-γ) in the magnum, isthmus and uterus (P < 0.05). However, the concentrations of the anti-inflammatory cytokines interleukin-4 (IL-4) and interleukin-10 (IL-10) in these tissues were significantly decreased (P < 0.05). Notably, dietary PP supplementation during the challenge phase significantly alleviated LPS-induced oviduct inflammation, as evidenced by decreased pro-inflammatory cytokine levels and increased anti-inflammatory cytokine levels in the oviduct (P < 0.05). Furthermore, significant interaction effects between LPS challenge and dietary PP supplementation were observed for inflammatory cytokines and glutathione (GSH) activity in the oviduct (P < 0.05). In summary, dietary PP supplementation improved production performance and alleviated oviduct inflammation in laying hens, potentially by modulating immune responses. These findings suggest that PP has potential as a functional feed additive for enhancing production and reproductive health.