Effects of Biologically Synthesized Iron Oxide Nanoparticles on Nutrient Composition, In Vitro Organic Matter Digestibility, and Methane Production of Dairy Cattle Feed

Objective: This study evaluated the effects of biologically synthesized iron oxide nanoparticles on nutrient composition, in vitro organic matter digestibility, metabolizable energy, and methane production of a dairy cattle concentrate feed.Material and Methods: Iron oxide nanoparticles synthesized using Prunus serrulata leaf extract were added to a commercial dairy concentrate at 0, 10, 20, and 30 milligrams per kilogram of dry matter. Feed samples were analyzed for dry matter, crude protein, crude ash, ether extract, neutral detergent fiber, acid detergent fiber, hemicellulose, and total carbohydrates. In vitro gas production with rumen fluid was used to determine methane production, organic matter digestibility, and metabolizable energy.Results: Nanoparticle supplementation did not affect dry matter, ether extract, acid detergent fiber, hemicellulose, organic matter digestibility, or metabolizable energy. Crude ash and crude protein increased with increasing dose, whereas neutral detergent fiber and total carbohydrates decreased. Methane production was significantly reduced at 20 and 30 milligrams per kilogram compared with the control, demonstrating dose-dependent suppression of ruminal methane formation.Conclusion: Biologically synthesized iron oxide nanoparticles reduced methane production without impairing feed digestibility or energy value, indicating strong potential as functional feed additives for improving rumen fermentation efficiency and reducing greenhouse gas emissions in dairy cattle.