Effects of dietary black soldier fly larvae meal inclusion on the serum metabolome of Silkie crossbreed chickens.

Abstract

INTRODUCTION: Black soldier fly larvae (BSFL;) meal, an alternative to conventional dietary protein sources, such as soybean meal, is rich in medium-chain fatty acids, antimicrobial peptides and other bioactive components. These components may modulate the composition and function of the gut microbiota or, after absorption, affect host metabolic pathways. We hypothesised that the functional effects of BSFL meal would be reflected in alterations in the serum metabolite profile of Silkie crossbreed chickens. METHODS: Serum samples from chickens fed a control soybean-based diet or a diet containing 150 g/kg partially defatted BSFL meal were analysed using untargeted liquid chromatography-mass spectrometry. RESULTS AND DISCUSSION: A total of 3304 metabolite features were detected, of which 1341 were annotated, with 777 retained for statistical analysis. Principal component analysis and PERMANOVA revealed a clear separation between dietary groups (= 0.001). Forty metabolites were significantly altered (FDR ≤ 0.05), with 31 more abundant and nine less abundant in the BSFL group. These shifts were characterised mainly by increased lipid-related metabolites, including medium-chain fatty acids (MCFAs) and phospholipids, indicating alterations in lipid metabolism. In addition, changes in amino acid derivatives and energy-related metabolites suggested the modulation of amino acid and energy metabolic pathways. Several metabolites with putative microbial origin were elevated, consistent with indirect host-microbiome metabolic interactions. These metabolic changes showed correlations with significantly higher average daily gain (= 0.02), numerically greater final live weight, and a reduced feed conversion ratio in BSFL-fed chickens (= 0.07 and= 0.08, respectively). Overall, dietary inclusion of 150 g/kg BSFL meal modified systemic metabolism without detectable negative effects on performance or serum biomarkers, suggesting that this level of BSFL inclusion can be beneficial for slow-growing Silkie chickens.