Zinc Glycinate Alleviates Necrotic Enteritis Infection in Broiler Chickens

This study evaluated zinc glycinate (ZG) on necrotic enteritis (NE) in chickens through two in vivo experiments and one in vitro experiment. In vivo, ZG was supplemented (study 1: 40–120 mg/kg; study 2: 100–160 mg/kg). In total, 192 (exp. 1) and 240 Cobb male birds (exp. 2) (n = 6) were studied for 28 days. ZG at 120 mg/kg significantly improved BWG by day 28 (p < 0.05), while 140 mg/kg reduced FCR (p < 0.05). Lesions were significantly reduced by 120 mg/kg (p < 0.01), and mortality was lowered by 80 mg/kg (study 1, p < 0.05) and 120 mg/kg (study 2, p < 0.01). ZG at 160 mg/kg increased IFN-γ expression in the spleen (p < 0.01), and 140 mg/kg decreased Zn/Cu SOD1 in the cecal tonsils (p < 0.05). In vitro, zinc (10–1000 µM) enhanced intestinal cell viability under Clostridium perfringens challenge. Cytotoxicity in HD-11 cells decreased significantly at concentrations ≥100 µM after 12 h (p < 0.001) and ≥10 µM after 24 h (p < 0.001), with the lowest levels observed at 100 µM (p < 0.001). We recommend increasing zinc to 120 mg/kg as ZG in poultry feed against NE infection.