Effects of replacing antibiotics with probiotics and antimicrobial peptides on performance, gut health, carcass traits, meat quality, and welfare in broilers infected with Eimeria and Clostridium perfringens.

This study evaluated the effectiveness of antibiotic, probiotic, and antimicrobial peptide (AMP) supplements in mitigating adverse consequences of necrotic enteritis (NE) in broilers. In total, 720 one-day-old (Ross-308) male broiler chicks were randomly assigned to five distinct feeding regimens (each treatment consisting of six replicates of 24 birds) including: (1) negative control (NC), fed only basal diet; (2) positive control (PC); with C. perfringens challenge + basal diet; (3) CP-Ab: challenged + virginiamycin (Stafac® 500) at 200 g/ton, (4) CP-Pro: challenged + 200 g/ton B. subtilis PB6 (Clostat dry®) probiotic additive, and (5) CP-LS2: challenged and fed an antimicrobial peptide (LassoTide Plus®) at 200 g/ton. The NE challenge was induced by administering 10X coccidia vaccine on day 15 followed by inoculation with a pathogenic field strain of C. perfringens type G (1 × 10 CFU/ml/ bird; 1 ml) on days 19 and 20 through oral gavage. Feeding AMP and probiotic to the NE-affected broilers resulted in 23.93% and 19.70% respectively higher body weight gain and 76.59% and 70.27% lower mortality compared to the PC. Similarly, supplementation with AMP improved (P < 0.05) gut morphology, carcass yield (5.82%), meat water holding capacity (14.73%), and reduced cooking loss (10.01%), dripping loss (20.87%), and shear force (25%) as compared to the PC. Additionally, the excreta score, litter quality and welfare attributes were significantly ameliorated (P < 0.05) with AMP addition. In conclusion, the findings suggest that AMP outperformed both virginiamycin and probiotic, demonstrating its potential as a superior substitute for AGPs in broilers.