Sustainable feed meets soil regeneration: the benefits of black soldier fly larvae frass for animals on exhibit
Citation
Koutsos L, Kuball C, Banks I, and Espinosa C. 2025. Sustainable feed meets soil regeneration: the benefits of black soldier fly larvae frass for animals on exhibit. In Treiber K, Brooks M, D’amato-Anderson J, Nylander J, Eds. Proceedings of the Sixteenth Conference on Zoo and Wildlife Nutrition, AZA Nutrition Advisory Group, Oklahoma City, OK.
Abstract
Black soldier fly larvae (BSFL) frass is the co-product of insect farming and consists of digested feed and chitin-rich exoskeletons from insect molting. It is a sustainable natural fertilizer (Beesigamukama, 2020; Chepkorir, 2024) and also approved for animal feed (AAFCO, 2025), making it suitable for application on pastures with animals on exhibit. BSFL frass can effectively replace synthetic N sources (e.g., urea) and improve quality and disease resilience in turfgrass and in other plants (Poveda, 2021), and has biopesticidal properties (Anedo, 2025). Animal feeding trials have consistently demonstrated palatability and safety of this ingredient as a component of animal diets. Indeed, BSFL frass can be included as a safe and effective ingredient at 2.5 to 10% in broiler diets (Adams and Koutsos, 2024), and at 3 to 6% in pig nursery diets (Rubio et al., 2025). BSFL frass also increased growth and enhanced resistance to bacterial diseases when included in diets for catfish (Yildrim-Aksoy et al., 2020a) and tilapia (Yildrim-Aksoy et al., 2020b). While care should be taken in sourcing frass, as input ingredients and processing conditions will impact nutrient concentrations and hazard assessments, overall BSFL frass can offer a safe, natural option for feeding plants and animals in pasture exhibits.
KoutsosIBSFLFrassZN2025S5.pdf 167 KB
