Composting organic waste from the broiler production chain: A perspective for the circular economy

The broiler production chain (BPC) has associated environmental impacts, costs, and effects that are not compensated by the Brazilian socioeconomy. The objective of this review was to discuss BPC waste composting from a circular economy perspective. Organic solid waste is a negative externality and the agroindustry must contribute to its internalization, especially in countries with significant production, consumption, and export of chicken meat. The BPC has four main stages of significant organic waste production: reproductive poultry, hatchery, broiler growth, and broiler industry. The principal residues of this industry are reproductive poultry litter, hatchery waste, feed waste, carcasses, truck cleaning solid fraction, flotation sludge, sausage casings, charcoal, and ash. These residues have varying characteristics, such as total organic carbon (TOC) from ranging 4.4–56.22% and nitrogen from 0.2 to 9.33%. It is evident that raw materials, nutrients, and energy are misused throughout the BPC; developing countries especially cannot sustain the loss of these valuable resources. Composting has emerged as a method for mitigating the impacts of BPC waste, however, there are some obstacles. The high nitrogen concentration in BPC residues make balancing the C/N ratio complex. This deficit carbon demands residues from other sectors, such as from tree pruning, cotton residues, raw glycerin, and Napier grass. The produced BPC compost has favorable attributes to be reincorporated into the supply chain as an agricultural input. However, little research has been conducted on the short, medium, and long-term impacts of BPC compost application on different crop and soil types. Cultivations close to BPC facilities which grow broiler feed components (e.g., corn) are attractive for a closed cycle strategy and for approaching the principles of the circular economy.