Effects of Nano-Iron Sulfide on Growth Performance, Antioxidant Status, Meat Quality, and Intestinal Microbiota in...

This study evaluated nano-iron sulfide (nFeS) as an iron source for bioavailability, biocompatibility, and tolerance in broilers. Broilers (Arbor Acres; males; initial body weight: 43.0 ± 0.4 g) were allocated between five diets: an iron-deficient basal diet (ID), or a basal diet with 80 mg Fe/kg as FeSO₄; or 20, 40, or 80 mg Fe/kg as nFeS. The results showed that nFeS treatments (40, 80 mg/kg) improved average daily gain and feed conversion rates compared to ID and showed comparable or even superior effects relative to FeSO₄ on growth performance within 1-21 days (p < 0.05). nFeS improved whole-blood hemoglobin (Hb) content and packed cell volume (PCV) percentages at day 21, while increasing serum SOD and GSH-Px activities at day 42. nFeS (40, 80 mg/kg) had or tended to deposit higher iron content in the liver, spleen, duodenum and serum than the FeSO₄ groups. nFeS significantly increased breast meat lightness and redness compared with ID (p < 0.05) and showed comparable effects on postmortem pH, drip loss, and shear force relative to FeSO₄. nFeS reshaped the microbial composition in the jejunum and cecum, particularly enriching the abundance of beneficial bacteria such as Lactobacillus in the jejunum. At a dose of up to 400 mg/kg, nFeS revealed no negative effects in broilers. In conclusion, nFeS is an effective iron supplement with high bioavailability and comparability, with additional benefits in shaping intestinal microbiota.