Sweet basil oil nanoparticles as novel feed additives: impacts on productivity, intestinal morphology, antioxidant capacity, and microbiota in laying hens.

OBJECTIVE: Nanotechnology has been suggested as a promising strategy for enhancing the stability and delivery efficiency of feed additives through the formation of nanoparticles (NPs). Sweet basil oil (SBO) contains a diverse range of bioactive constituents; however, its intestinal-targeted delivery remains limited. Therefore, this study aimed to determine the effects of sweet basil oil nanoparticles (SBO-NPs) on egg production and egg quality, intestinal morphology, antioxidant capacity and cecal microbiota in laying hens. METHODS: A total of 225 Roman Brown laying hens at 25 weeks of age were randomly assigned to three treatments with five replicates of 15 birds in a completely randomized design (CRD). Dietary treatments were as follows: (i) basal diet (Con), (ii) basal diet with free sweet basil oil (SBO) at 500 ppm, (iii) basal diet with SBO nanoparticles at 500 ppm (SBO-NPs), respectively. The experiment was conducted for 10 weeks, during which egg production and quality, antioxidant capacity, intestinal morphology, and cecal microbiota were assessed. RESULTS: Dietary SBO-NPs significantly increased egg production than SBO and Con diets (p < 0.01). However, all additives had no effect on feed conversion ratio and egg quality (p > 0.05). SBO-NPs markedly improved villus height and villus surface area (p < 0.05). Furthermore, superoxide dismutase activity in duodenum and liver were increased by SBO-NPs. Malondialdehyde levels were significantly reduced by 52-53% in the SBO-NPs group compared to the Con group (p < 0.05). In contrast, the cecal microbiota remained broadly similar among treatments at the phylum and genus levels with no significant differences in the alpha and beta diversity. CONCLUSION: The results demonstrated that the SBO-NPs enhanced egg production by improving intestinal morphology, increasing antioxidant capacity, and reducing lipid peroxidation.