Valorization of poultry feather with poultry litters and evaluation of effects on the microbial biota, minerals and plant growth potential

Abstract

The persistence and accumulation of keratin-rich poultry feathers contribute to environmental pollution and inefficient waste disposal due to their resilient structure. Poultry litter, however, may serve as a co-substrate to enhance microbial biodegradation of feathers, thereby reducing greenhouse gas emissions and improving nutrient recovery. This study evaluated microbial and biochemical interactions during the co-degradation of feathers and poultry litter. Microbial counts (bacteria and fungi), mineral composition, and optimal substrate ratios were determined. Controlled degradation experiments in different ratios of poultry feathers to litters revealed that weight of feathers (5 g) and litter (5 g) supported the highest microbial activity. Bacterial counts increased from 1.3 × 10³ to 3.1 × 10⁴ CFU/ml, while fungal counts rose from 1.6 × 10² to 2.0 × 10⁵ CFU/ml. Mineral analyses showed significant variations before and after degradation. The feather–litter mixture produced the highest phosphorus concentration post-degradation (14.710 mg/L), while feather-only treatments retained the most nitrogen (27.58 g/L) and potassium (12.760 mg/L). These results demonstrated that feathers delivered consistent nitrogen, while litter supplied phosphorus, potassium and organic carbon to the substrate, establishing a balanced setting that promoted microbial growth. By transforming feathers and litter into nutrient-rich hydrolysates, this strategy provides a sustainable alternative for soil amendment, reduces environmental pollution, and promotes circular bioeconomy practices.