Insect larvae meal as a feed ingredient for Atlantic salmon (Salmo salar) : effects on intestinal function, health, and microbiota

• Main Author: Li, Yanxian
• Other Authors: Krogdahl, Åshild, Kortner, Trond
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Norwegian University of Life Sciences, Ås 2021
• Subjects: Atlantic salmon; Insect meal; Gut health; Microbiota; Salmo salar
• Online Access: https://hdl.handle.net/11250/3055380

Being part of fish’s natural diets, insects have become a realistic, sustainable feed ingredient for aquaculture. While insects’ nutritional values have been extensively studied in numerous fish species, their impact on the fish health remains to be fully explored. The intestine is the main organ directly interact with the diet and of pivotal importance for the growth, development, and protection against pathogens. A well-functioning, healthy intestine is the key to convert feeds into fish biomass efficiently. In this thesis, two feeding trials, one in freshwater and one in seawater, were conducted to generate new knowledge regarding the effects of insect meal diets on the intestinal function, health, and microbiota in Atlantic salmon. The results showed no clear evidence that insect meal diets containing 15% or 60% black soldier fly larvae meal impaired the intestinal function or health in Atlantic salmon. On the contrary, insect meal diets improved intestinal health status by reducing excessive lipid deposition in the proximal intestine. Despite a four-time difference in the insect meal inclusion level between the two feeding trials, the insect meal diets reproducibly modulated the salmon intestinal microbiota enriching a particular group of bacterial genera dominated by members of the Bacillaceae family. The present thesis work generated new knowledge regarding how diets containing insect meal may influence the intestinal function, health, and microbiota in Atlantic salmon. It strengthens the knowledge basis for applying insect meal in aquaculture at a full scale. For å sikre matvareforsyningen til en stadig økende befolkning med begrensede råvareressurser, må matproduksjonssektoren minimere ressursinnsats og maksimere ernæringsverdi for humant konsum. Moderne laksefôr inneholder mye planteråvarer som også kan brukes til matproduksjon. For å bidra en bærekraftig utvikling av lakseoppdrett, må næringen redusere sin avhengighet av fôrråvarer som konkurrerer med humant konsum, og i større grad ta i bruk ...