Utilization of Agro Wastes into Animal Feed through Solid-State Fermentation

Abstract— The regions of Southeast Asia generate significant quantities of underused agro-industrial residues that include sago hampas and rice bran and palm kernel cake (PKC) and cassava peels while these materials hold substantial nutritional value. This review is prepared in accordance with PRISMA guidelines examines current research (2015–2025) about transforming agricultural leftovers into improved animal feed through solid-state fermentation (SSF). Thirty-three relevant studies examined microorganisms such as Aspergillus, Trichoderma and Bacillus and lactic acid bacteria together with fermentation conditions that improved animal nutritional quality alongside performance outcomes. During SSF the protein content increased by up to 30–35% in PKC while fiber fractions decreased specifically cellulose and hemicellulose and anti-nutrient effects were observed with cyanogenic glycosides and phytates reduction. The study identified fermented PKC together with rice bran as protein concentration feeds which benefit both monogastric and ruminant animals and fermented cassava peels alongside sago hampas function as digestible energy sources through supplementary nitrogen use. The fermentation process through SSF led to various co-benefits which improved digestive capacities and gut health together with elevated feed conversion for poultry, swine, fish and ruminant livestock. The utilization of SSF faces ongoing operational hurdles because fermentation needs scale-up alongside microbial safety controls and feed maintenance stability. The sustainability solution of SSF meets circular agriculture's criteria through waste transformation for animal feed production while decreasing imported ingredient use and protecting the environment. The research evidence indicates that implementing SSF technology throughout Southeast Asia requires government backing together with staff training sessions and the establishment of scalable technological solutions to support broader adoption.