Effect of replacement of soybean oil by Hermetia illucens fat on performance, digestibility, cecal microbiome, liver transcriptome and liver and plasma lipidomes of broilers

Abstract

Background In contrast to protein-rich insect meal, the feed potential of insect fat is generally less explored and knowledge about the suitability of insect fat as a fat source specifically in broiler diets is still limited. In view of this, the present study aimed to comprehensively investigate the effect of partial (50%) and complete replacement of soybean oil with insect fat from Hermetia illucens (HI) larvae in broiler diets on performance, fat digestibility, cecal microbiome, liver transcriptome and liver and plasma lipidomes. Thus, 100 male, 1-day-old Cobb 500 broilers were randomly assigned to three groups and fed three different diets with either 0 (group HI-0, n = 30), 2.5% (group HI-2.5, n = 35) or 5.0% (HI-5.0, n = 35) Hermetia illucens (HI) larvae fat for 35 d. Results Body weight gain, final body weight, feed intake, and feed:gain ratio during the whole period and apparent ileal digestibility coefficient for ether extract were not different between groups. Cecal microbial diversity did not differ between groups and taxonomic analysis revealed differences in the abundance of only four low-abundance bacterial taxa among groups; the abundances of phylum Actinobacteriota, class Coriobacteriia, order Coriobacteriales and family Eggerthellaceae were lower in group HI-5.0 compared to group HI-2.5 (P < 0.05). Concentrations of total and individual short-chain fatty acids in the cecal digesta were not different between the three groups. Liver transcriptomics revealed a total of 55 and 25 transcripts to be differentially expressed between groups HI-5.0 vs. HI-0 and groups HI-2.5 vs. HI-0, respectively (P < 0.05). The concentrations of most lipid classes, with the exception of phosphatidylethanolamine, phosphatidylglycerol and lysophosphatidylcholine in the liver and cholesterylester and ceramide in plasma (P < 0.05), and of the sum of all lipid classes were not different between groups. Conclusions Partial and complete replacement of soybean oil with HI larvae fat in broiler diets had no effect on growth performance and only modest, but no adverse effects on the cecal microbiome and the metabolic health of broilers. This suggests that HI larvae fat can be used as an alternative fat source in broiler diets, thereby, making broiler production more sustainable.

Implementation of a metabolizable energy regression model for black soldier fly larvae fat in broiler chicken diets: effect on growth performance, nutrient digestibility, and selected physiological indices

“…Prior to estimating the energy density of HI larvae fat, most authors assumed that AME N corrected to zero nitrogen balance AME N of insect fat was similar to that of soybean, maize or coconut oils, and that the fat energy density was applied at a 1:1 ratio in poultry diets (Schiavone et al, 2017;Kim et al, 2020a;b). This suppositions were consistent with the results of Schäfer et al (2023), who calculated the AME N for broilers using the following equation: AME N = 2732.628 + 62.865 × fat inclusion (%). However, the aforementioned studies assumed uniform AME N levels for each feeding period; thus, the validity of the AME N regression model proposed by Kierończyk et al (2022) for HI larval fat in broiler nutrition was only partially evaluated.…”

Effect of replacing soybean meal with Hermetia illucens meal on cecal microbiota, liver transcriptome, and plasma metabolome of broilers

“…Transcripts were classified as differentially expressed when the FC was > 1.3 or < -1.3 and the P -value was < 0.05. Similar cut-off values were used in recent studies for the selection of differentially expressed genes ( Gessner et al, 2019 ; Ringseis et al, 2019 ; Schäfer et al, 2023b ). In order to identify enriched Gene Ontology ( GO ) terms the differentially expressed transcripts were uploaded into the Database for Annotation, Visualization, and Integrated Discovery 6.8 bioinformatic resource to perform a gene set enrichment analysis ( GSEA ) ( Da Huang et al, 2009 ).…”

Effects of a biotechnologically produced Pleurotus sapidus mycelium on gut microbiome, liver transcriptome and plasma metabolome of broilers

“…The differentially expressed transcripts were filtered based on a FC > 1.3 or < -1.3 and a P -value < 0.05 between groups PSA-5.0 vs. PSA-0 and groups PSA-2.5 vs. PSA-0. Identical or similar filter criteria were also applied in several recent studies ( Ringseis et al, 2019 ; Grundmann et al, 2023 ; Schäfer et al, 2023 ). Gene set enrichment analysis ( GSEA ) was performed with the identified differentially expressed transcripts in order to identify enriched Gene Ontology ( GO ) terms within GO category biological process ( BP ), molecular function ( MF ) and cellular component ( CC ) and Kyoto Encyclopedia of Genes and Genomes ( KEGG ) pathways using the Database for Annotation, Visualization and Integrated Discovery bioinformatic resource 6.8 ( Huang et al, 2009 ; Sherman et al, 2022 ).…”