Potential, challenges, and research progress of Tenebrio molitor as a protein supplement for ruminants: a review
With growing demand for animal protein and increasing pressure on conventional feed resources, Tenebrio molitor ( T. molitor ) has emerged as a promising alternative protein source due to its high protein content, favorable fatty acid profile, efficient production, and ability to valorize agricultural by-products. This review summarizes the biological and nutritional characteristics of T. molitor , together with the rearing and processing factors affecting its suitability for animal feeding, with particular emphasis on its potential use in ruminant diets. Current evidence indicates that T. molitor larvae, the main form used in feed, have relatively low chitin content and generally good palatability and digestibility. Their nutritional value is influenced by rearing substrate, stocking density, and environmental conditions. Processing methods such as defatting, fermentation, enzymatic hydrolysis, and high hydrostatic pressure may improve nutrient availability and reduce limitations associated with lipid content and chitin. In vitro studies suggest that T. molitor meal can modulate rumen fermentation, with potential benefits for methane reduction, rumen-undegradable protein supply, and post-ruminal nutrient digestibility. However, in vivo evidence remains scarce, and its effects on animal performance are not yet fully understood. Large-scale application is further constrained by safety concerns, regulatory heterogeneity, market acceptance, and cost. Future studies integrating multi-omics, techno-economic analysis, and life cycle assessment are needed to clarify its nutritional, physiological, and environmental impacts and to support standardized production and safety evaluation.