ABSTRACT

Background and Aim: Cassava (Manihot esculenta) processing generates large quantities of residues that represent an abundant yet underutilized resource for sustainable dairy production, particularly in tropical and subtropical regions. These residues, including cassava pulp, peels, mixed processing residues, foliage, and other industrial by-products, have considerable potential as circular energy feed ingredients due to their high fermentable carbohydrate content and regional availability. However, their practical use remains constrained by substantial variability in nutrient composition, cyanogenic glycoside content, high moisture content, rapid spoilage, and inconsistent quality across processing streams. This review critically evaluates the current evidence regarding the classification, nutritional characteristics, physical properties, safety constraints, preservation technologies, and practical feeding applications of cassava processing residues in dairy cows within the framework of a circular bioeconomy. Particular emphasis is placed on stream-specific variability arising from processing methods, starch recovery efficiency, cultivar, season, and post-processing handling, as these factors directly influence feeding value and ration formulation. Major safety challenges, including hydrogen cyanide, fungal spoilage, mycotoxin contamination, microbiological hazards, and inorganic contaminants, are discussed together with recent advances in hazard mitigation. The review highlights technology-enabled stabilization approaches, including drying, ensiling, microbial inoculation, fermentation, and integrated detoxification strategies, that improve preservation, aerobic stability, feed safety, and nutritional consistency. Available dairy feeding studies indicate that properly stabilized cassava processing residues can partially replace conventional cereal-based energy sources when incorporated at appropriate dietary inclusion levels and balanced with adequate physically effective fiber and rumen-degradable nitrogen. Conversely, excessive inclusion or inadequate stabilization may compromise rumen function, reduce milk production, and impair milk quality. A practical framework emphasizing specification-based procurement, analytical quality control, rapid stabilization, and ration level management is proposed to facilitate the safe and efficient incorporation of cassava residues into dairy production systems. Overall, cassava processing residues represent promising circular feed resources that can enhance resource-use efficiency, reduce feed costs, minimize agro-industrial waste, and support environmentally sustainable dairy production. Nevertheless, wider adoption will require standardized quality specifications, improved preservation technologies, robust safety monitoring, and further validation through long-term commercial feeding trials and integrated economic and life cycle assessments.

Keywords: aerobic stability, cassava processing residues, circular bioeconomy, cyanide detoxification, dairy cows, ensiling, feed safety, tropical dairy systems.