Fermented Gallus gallus foot keratin-bone composites as peptide-mineral concentrate for aquafeed: ratio-dependent...

This research establishes baseline compositional data for fermented Gallus gallus foot keratin-bone composites to generate a peptide-mineral concentrate candidate to partially replace other feed ingredients of animal origin in aquaculture. Cofermentation with Saccharomyces cerevisiae and Lactiplantibacillus plantarum (1:1; 5% inoculum) was carried out at 30 °C for 28 days across five keratin-bone composite ratios (T₁-T₅). Proximate parameters-moisture, crude protein, fat, fiber, and ash-were quantified through standardized gravimetric and colorimetric methods; results were subjected to one-way multivariate analysis of variance, univariate analysis of variance, and Pearson correlation analysis.

Significant compositional differences were observed among treatments (Wilks' Λ = 4.64 × 10⁻¹², p < < 0.001), with large effect sizes for all parameters (η² ≥ 0.87). The highest protein content (76.67%, dry weight) occurred in exclusive keratinous biomass, whereas ash content peaked at 26.26% in exclusive bone residues. Moisture, protein, fat, and fiber positively covaried (r ≥ .934) and contrasted strongly with ash (|r| ≥ 0.905). Formulations may therefore be theoretically tuned to align with dietary strategies for certain ontogenetic stages, pending validation against species-specific requirement data and feeding trials. Validation through in vivo digestibility and amino acid profiling is further recommended; without such validation, the findings remain preliminary and limited to compositional characterization.