Insect-based ingredients in livestock feed

This chapter systematically evaluates three commercially viable insect species for livestock nutrition: black soldier fly (Hermetia illucens, BSF), yellow mealworm (Tenebrio molitor, YMW), and mulberry silkworms (Bombyx mori, MSW). While BSF and YMW are widely produced for feed due to their scalability and bioconversion efficiency, MSW is included because its pupae are readily available as a sericulture by-product. These species exhibit favorable biological characteristics, such as rapid growth rates and nutrient-dense profiles rich in immunomodulatory bioactive compounds; consequently, they offer significant potential for industrial scalability. In poultry production systems, dietary BSF incorporation at 10–12% inclusion rates sustains or enhances growth performance, feed conversion efficiency, and intestinal functionality while inducing beneficial shifts in cecal microbiota composition. Comparable responses are observed in laying hens, with improvements in egg quality indices and yolk pigmentation. YMW demonstrates similar efficacy, in terms of performance and feed efficiency at inclusion thresholds below 7.5%, while the MSW maintain adequate performance at moderate levels (4–10%), though antinutritional factors limit higher inclusion rates. In swine diets, the inclusion of 4–12% BSF larvae meal maintains productive performance while enhancing gastrointestinal health, with its lipid fraction also functioning as an efficient energy substrate. The inclusion of YMW at levels up to 10% supports growth dynamics and augments apparent ileal protein digestibility with beneficial microbiota modulation. In rabbits and ruminants, despite relevant EU regulatory limitations, insect lipids and protein meals can effectively replace conventional feedstuffs while maintaining performance. Moreover, they offer potentiality in mitigating methane production in ruminants. From an environmental sustainability perspective, insect- based ingredients demonstrate potential advantages in greenhouse gas mitigation and land-use efficiency. Nevertheless, life cycle assessments indicate that benefits exhibit substantial context-dependency, being maximized when production systems utilize low-value agro-industrial by-products as rearing substrates. Contemporary constraints encompass economic competitiveness, regulatory frameworks, compositional variability, and stakeholder acceptance. Future advancement necessitates technological innovation, process optimization, standardization, and regulatory harmonization. Overall, insect-derived ingredients constitute promising alternative feed resources whose sustainability credentials require validation within specific production contexts.