Gut health and vaccination response in pre-smolt Atlantic salmon (Salmo salar) fed black soldier fly (Hermetia illucens) larvae meal. Issue 86 (March 2019)

• Record Type: Journal Article
• Authors: Li, Yanxian; Kortner, Trond M.; Chikwati, Elvis M.; Munang'andu, Hetron Mweemba; Lock, Erik-Jan; Krogdahl, Åshild
• Is Part Of: Fish & shellfish immunology. Issue 86(2019)
• Page Start: 1106
• Page End: 1113
• Publication Date: 2019-03
• Subjects: Black soldier fly larvae -- Atlantic salmon -- Gut health -- Immune response -- Antibody -- Vaccination; Fishes -- Immunology -- Periodicals; Shellfish -- Immunology -- Periodicals; Poissons -- Immunologie -- Périodiques; Crustacés -- Immunologie -- Périodiques; 571.9617
• DOI: 10.1016/j.fsi.2018.12.057
• Languages: English
• ISSNs: 1050-4648

Abstract

Abstract: Limited availability of sustainable feed ingredients is a serious concern in salmon aquaculture. Insects may become an important, sustainable resource for expanding the raw material repertoire. Herein, we present data from an 8-week feeding trial with pre-smolt Atlantic salmon (initial body weight 49 ± 1.5 g) fed either a reference diet containing fish meal, soy protein concentrate and wheat gluten as protein sources, or a test diet wherein 85% of the protein was supplied by black soldier fly larvae meal. Possible diet effect on the systemic immune response was evaluated by measuring plasma antibody titers after vaccination against infectious pancreatic necrosis virus (IPNV). The gut health of fish was evaluated using endpoints including organ and tissue indices, histopathological parameters and gene expression. Both diets induced the same level of antibody responses against IPNV. In fish fed the reference diet, the histological examination of the pyloric caeca mucosa showed clear hyper-vacuolization suggestive of lipid accumulation in enterocytes, whereas this was less pronounced in the insect meal fed fish. Expression of genes relevant to lipid metabolism confirmed these histological findings. Immune and barrier-function gene expression profiles were both generally not affected by diet. However, the fish fed insect meal showed increased expression of genes indicative of stress response, immune tolerance and increased detoxification activity. In summary, our results showed no indications that dietary inclusion of insect meal affected the gut health of Atlantic salmon negatively. The insect meal based diet seemed to reduce excessive lipid deposition in the pyloric caeca and stimulate xenobiotic metabolism. Highlights: Increased, positively correlated expression of cd3γδ and foxp3 in the intestine of fish fed insect meal diet. Insect meal diet was not superior over commercial diet in increasing antibody titers after viral vaccination. Reduced enterocyte hyper-vacuolization in the proximal intestine of fish fed insect meal diet. Increased expression of genes indicative of stress response and detoxification activity in fish fed insect meal diet.