Biodegradation of antibiotic residues in chicken manure by composting processes

Chicken manure is rich in macro and micro nutrient compared to livestock manures. Unfortunately, it may also contain higher antibiotic residues that has to be minimized before applying as a manure. The objective of this research was to eliminate antibiotic residues in chicken manure using three kinds of decomposer. The experiment was conducted in greenhouse conditions. A completely randomized design with 5 replications was applied. The treatments consisted of chicken manure (CM) with 40% water content, composting CM with local microorganisms (MOL), composting CM with Consortium of Cellulolytic Fungi (CCF), and composting CM with commercial decomposer. Parameters measured were the content of Tetracycline, C, C/N, and CO₂ evolution. The results showed that applying microbial decomposer eliminated 100% Tetracycline residues after 4 weeks composting. The C content and C/N decreased 34.8 to 41.8% and 15.46 to 20.30% after 6 weeks composting, respectively. The highest CO₂ evolution resulted from the application of CCF and commercial decomposers. Composting chicken manure by CCF or commercial decomposer prior to be used as organic fertilizer are promising to eliminate antibiotic residues.