Two-Stage Fermented Feather Meal Enhances Growth Performance and Amino Acid Digestibility in Broilers

The study aimed to investigate the dose tolerance of enzymatically degraded feather meal (EFM) in the diet, and the effect of the two-stage fermented feather meal on the growth performance and amino acid digestibility of broilers. In trial 1, 160 one-day-old broilers were randomly assigned into 0, 10, 15, and 20% EFM groups. In trial 2, 160 one-day-old broilers were randomly assigned into control, 10% EFM, Bacillus subtilis var. natto N21 + B. coagulans L12 fermented EFM (BBEFM), and B. subtilis var. natto N21 + Saccharomyces cerevisiae Y10 fermented EFM (BSEFM) groups. Trial 3 involved 32 twenty-one-day-old male broilers randomly assigned into nitrogen-free diet, highly digestible protein, EFM, and BSEFM groups for a 7-day metabolic trial. During all of the feeding periods, increasing the EFM dosage in the diet linearly and quadratically inhibited weight gain (WG), feed intake, and feed conversion ratio (FCR) (p p > 0.05). Dietary inclusion of more than 15% resulted in a negative impact on growth performance over days 1–35 (p p p Bacillius subtilis var. natto N21 + S. cerevisiae Y10 fermentation can improve the amino acid digestibility of EFM and enhance broiler growth performance