Growth Performance, Diet Digestibility, and Chemical Composition of Mealworm ( Tenebrio molitor L.) Fed Agricultural By-Products

• Published in: Insects (Basel, Switzerland) Switzerland), 2023-10, Vol.14 (10), p.824
• Main Authors: Montalbán, Ana, Martínez-Miró, Silvia, Schiavone, Achille, Madrid, Josefa, Hernández, Fuensanta
• Format: Article
• Language: English
• Subjects: Agribusiness; Agricultural research; Agricultural wastes; Amino acid composition; Amino acids; Analysis; Animal feed; Animal protein; Beetles; Bioconversion; Biomass; Body mass; Bread; Broccoli; By products; Byproducts; Carbohydrates; Chemical composition; Circular economy; Conversion ratio; Diet; Digestibility; Emissions; Feed conversion; Feed utilization efficiency; Feeds; Food; Food sources; grape pomace; Grapes; Greenhouse gases; Humidity; insect; insect larvae; Insects; Larvae; Livestock; Livestock production; Nutrition; Nutritional aspects; Nutritive value; Physiological aspects; Productivity; protein source; Protein sources; Proteins; Pulp; Substrates; Sustainable production; Tenebrio molitor; tigernut pulp; Uric acid; Vegetables
• ISSN: 2075-4450; 2075-4450
• DOI: 10.3390/insects14100824

Humanity's growing demand for animal protein exceeds the capacity of traditional protein sources to support growing livestock production. Insects offer promising partial substitutes, converting low-nutritional quality materials into high-value biomass. Hence, the bioconversion ability of larvae was assessed by using three types of agricultural by-products (broccoli by-product, tigernut pulp, and grape pomace) at different inclusion levels (0%, 25%, 50%, and 100%) in a carbohydrate-based diet. Ten diets were formulated to assess their impact on the growth, diet digestibility, and nutritional composition of the larvae. For each treatment, eight replicates were employed: five for the growth-performance-digestibility trial and three for the complementary test of uric acid determination. The growth was influenced by the type of diet administered. The broccoli by-product resulted in higher larvae weight and a better feed conversion ratio. However, diets based solely on a single by-product (100%) compromised the productivity and diet digestibility. The larvae changed their nutritional composition depending on the rearing substrate, although the amino acid profile remained consistent. In conclusion, the studied by-products have the potential for use in rearing as part of the diet but not as the exclusive ingredients, indicating promising opportunities for using agricultural by-products in rearing and production.