Enhanced Efficacy of Pomegranate Peel Extract via Double Nano-Emulsion Delivery in Laying Hens: Impact on Performance, Immunity, Antioxidant Status, and Salmonella Typhimurium Resistance

Abstract

Multidrug-resistant (MDR) Salmonella Typhimurium, largely spread through poultry products, increasingly resists antibiotic treatment. We evaluated dietary pomegranate peel extract-loaded nano-emulsions (PomNEs) on performance, immunity, antioxidant capacity, and S. Typhimurium resistance in laying hens. A total of 250 15-week-old Hy-Line Brown hens received a basal diet or diets supplemented with PomNEs at 0.3, 0.6, or 1.2 g/kg, and then were challenged with S. Typhimurium at 34 weeks. Hens fed PomNEs, especially PomNEs1.2, showed improved egg production and feed efficiency before challenge and restored normal output afterward. Supplementation reduced Salmonella colonization in the ovaries, liver, and eggs, with considerable reduction in eggs and ovaries at the highest dose by ten weeks, and down-regulated bacterial virulence genes (hilA, invA). Immune function improved through higher phagocytic activity, intracellular killing, and lysozyme levels, lower nitric oxide, up-regulated IgA and β-defensins (AvBD6, AvBD12), and suppressed pro-inflammatory cytokines and chemokines. Intestinal and ovarian redox balance improved via reduced COX2 and elevated GPX-1, HO-1, NQO1, SOD-1, and CAT expression. These benefits support PomNEs as promising natural feed additives to enhance laying performance, antioxidant defense, and immunity against salmonellosis, offering a sustainable strategy for supporting disease control in poultry production.