| Summary: | 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, <i>Bacillus subtilis</i> var. <i>natto</i> N21 + <i>B. coagulans</i> L12 fermented EFM (BBEFM), and <i>B. subtilis</i> var. <i>natto</i> N21 + <i>Saccharomyces cerevisiae</i> 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) (<i>p</i> < 0.05), except the FCR at 22–35 days (<i>p</i> > 0.05). Dietary inclusion of more than 15% resulted in a negative impact on growth performance over days 1–35 (<i>p</i> < 0.05). Therefore, the EFM dose tolerance in the broiler diet is 10%. The WG, FCR, and production efficiency factor of the BSEFM group were better than those of the control group in days 1–35 (<i>p</i> < 0.05). The apparent and standardized ideal amino acid digestibility of BSEFM was higher than EFM in trial 3, except for Met, Cys, and Trp (<i>p</i> < 0.05). In conclusion, the EFM dose tolerance for the broiler diet is 10%. <i>Bacillius subtilis</i> var. <i>natto</i> N21 + <i>S. cerevisiae</i> Y10 fermentation can improve the amino acid digestibility of EFM and enhance broiler growth performance.
|
|---|