Available for millions of years but discovered through the last decade: Insects as a source of nutrients and energy in animal diets

Impact of mediterranean fruit fly rearing residues and biological supplementation on performance of gimmizah chicks

For a transformation of the global food system towards sustainability, circular approaches and nutrient-rich side-stream valorization are mandatory. Moreover, affordable and sustainable alternatives to corn, soy, and fish meal are needed in poultry production. Recently, insects and their derived products have gained research interest as alternative sources of conventional feed ingredients in poultry nutrition. The Mediterranean fruit fly (medfly; Ceratitis capitata) production industry using sterile insect technology amasses thousands tonnes of rearing residues annually. This study is the first to shed light on the potential use of medfly rearing residues (MFRR), as a partial replacement for corn and soybean in Gimmizah chicks' diets, with or without biological supplementation (BS). It evaluates their effects on growth, carcass characteristics, blood indices, serum biochemical and histological changes in internal organs. A 7-week trial was conducted using 240, 15-day-old Gimmizah chicks, which were randomly divided into four groups (6 replicates, 10 birds each): the first group (T1) was fed a corn-soybean control diet, the 2nd group (T2) fed the control diet enriched with 1 ml BS/kg diet. The 3rdgroup (T3) received the control diet after replacing 10 % of corn and soybean with MFRR meal, while the 4th group (T4) fed the 10 % replacement by MFRR combined with 1 ml of BS. All groups received isoenergetic and isoprotienic diets with free access to feed and water for 49 days trial period. Compared to the control, both BS and MFRR inclusion with or without BS (T4 and T3, respectively) positively improved body weight, feed consumption, feed conversion, performance index and carcass yield. Blood analysis showed increased red blood cells, hemoglobin, packed cell volume, total protein, albumin, globulins, triglycerides, cholesterol, thyroxine hormone, uric acid and creatinine, with no adverse histological alteration in the bursa or intestine. In conclusion, the study suggests that MFRR can effectively replace 10 % of traditional feed ingredients, with or without BS, enhancing chicks' performance and health. Further future studies are recommended for broader application of MFRR in poultry nutrition.

Assessing the performance, egg quality, serum analysis, heavy metals and essential trace metals accumulation in laying hen eggs and tissues fed black soldier fly (Hermetia illucens) larvae meal

Black soldier fly (BSF) larvae convert wastes into protein, playing a vital role in addressing the challenge of sustainable poultry production. These larvae accumulate toxic substances, posing a risk to feed and food safety. This study investigates the effects of substituting soybean meal with different levels of BSF larvae meal on laying performance, egg quality, serum analysis, and the deposition of various metals in eggs, meat, and excreta. A total of 1,008 Lohmann hens (age 48 wk) were randomly assigned to 4 treatments. The treatments consisted of corn-soybean meal (CK) diet replaced with 7% (BSF7), 14% (BSF14), and 21% (BSF21) BSF larvae meal. Each treatment consisted of 6 replicates with 42 hens each and the trial lasted for 8 wk. Dietary BSF larvae meal treatments increased (linear, P < 0.05) the laying rate (1.52 to 1.95%) and decreased (linear, P < 0.01) the feed intake (3.64-3.86 g) during the entire experiment. During 48 to 52 wk, egg weight was decreased (P < 0.001) 0.93 g for the BSF21 group compared to CK group, however, during 52-56 wk, no differences in egg weight were observed among treatments. The addition of BSF larvae meal enhanced the eggshell strength (linear, P < 0.05), with no effect on the albumen height and yolk weight (P > 0.05). Low transfer of arsenic, lead, and cadmium concentration was observed in the egg yolk and egg white across different treatments (P > 0.05). Conversely, the concentrations of these metals and iron showed an increase, while Zinc exhibited a decrease in excreta as the dietary intake of BSF larvae meal increased. The chromium and iron increased linearly (P < 0.001) in the egg white with the inclusion of BSF larvae meal. Egg white iron and chromium showed a strong positive correlation with the dietary zinc and copper. Taken together, BSF larvae can replace soybean meal completely in laying diet, however, careful attention requires to elevated metal levels in diet and excreta.

Inclusion of Tenebrio molitor larvae meal in the diet of barbary partridge (Alectoris barbara) improves caecal bacterial diversity and composition

In this study, we investigated the influence of the inclusion of Tenebrio molitor (TM) larvae meal in the diet on the diversity and structure of the bacterial community in the caecal content of Barbary partridges. A total of 36 partridges, selected randomly for slaughter from 54 animals, were divided equally into three treatment groups, including the control group (C) with a diet containing corn-soybean meal and two experimental groups, in which 25% (TM25) and 50% (TM50) of the soybean meal protein was replaced by the meal from TM larvae. After slaughtering, the bacterial community of the 30 caecal samples (10 samples per each experimental group) was analysed by high-throughput sequencing using the V4-V5 region of the 16 S rRNA gene. Alpha diversity showed a higher diversity richness in the TM50 group. Beta diversity showed statistical dissimilarities among the three groups. Firmicutes was the dominant phylum regardless of the diet, with the predominant families Ruminococcaceae and Lachnospiraceae. Clostridia and Faecalibacterium were decreased in both TM groups, Lachnospiraceae was suppressed in the TM50 group, but still this class, genus and family were abundantly present in all samples. Several potentially beneficial genera, such as Bacillus, Ruminococcaceae UCG-009, Oscillibacter and UC1-2E3 (Lachnospiraceae) were increased in the TM50 group. The results showed a beneficial effect of the T. molitor larvae meal on the caecal microbiota of Barbary partridges, particularly in the TM50 group, which showed an increase in bacterial diversity.

Cutting-edge exploration of insect utilization in ruminant nutrition-feature and future: a systematic review and meta-analysis

There has been a growing interest in using insects as sustainable protein sources for ruminant feed, such as the adults of the two-spotted cricket (Gryllus bimaculatus), larvae of the mealworm beetle (Tenebrio molitor), black soldier fly (Hermetia illucens), and pupae of the silkworm (Bombyx mori). The advantages of these insects over other plant materials lie in their elevated levels of crude protein and fat. However, this interest lacks a comprehensive understanding of the impact of insects on the ruminal fermentation processes, including digestibility and gas production, as well as the impact on animal performance and related health aspects. This review offers a comprehensive analysis of ruminal fermentation indices across diverse insect species. Employing descriptive and meta-analysis methodologies, we examined the impact of incorporating insect-derived meals in ruminants' diets. Moreover, we evaluated the growth performance and biochemical parameters of blood in ruminants when species such as Tenebrio molitor, Hermetia illucens, Oriental Hornet (Vespa Orientalis), and Bombyx mori were incorporated into ruminants' diets. The meta-analysis was performed on a limited dataset of 14 in vitro and eight in vivo trials, investigating insect meal as a potential feed source. A comparison is drawn between these insect-based feeds and conventional dietary sources such as soybean meal, alfalfa hay, and commercial concentrate diets. Our meta-analysis revealed that incorporating Gryllus bimaculatus and Hermetia illucens to partially replace protein sources in ruminants' diet did not adversely affect digestibility, ruminal fermentation, and ruminant production, supporting the feasibility as a feed ingredient for ruminant animals. In addition, the oriental hornet showed an overall higher outcome on the final BW, ADG, digestibility, and volatile fatty acid (VFA) production, suggesting the promising effect of this insect for future use in ruminants. The data also indicates that dietary insect inclusion levels should not exceed 30% (DM basis) to achieve an optimal ruminal fermentation profile. Furthermore, it offers comparative insights into the nutritional value of these insects, which warrant further investigation at the in vivo level. Ultimately, the existing understanding of the nutritional utilization potential of these insects by ruminants, particularly concerning macro- and micronutrients, is evaluated and revealed to be significantly constrained.

Effects of Black Soldier Fly Larvae Oil on Growth Performance, Blood Biochemical Parameters, Carcass Quality, and Metabolomics Profile of Breast Muscle of Thai Native Chickens

This study aimed to evaluate the effects of the replacement of rice bran oil (RBO) with black soldier fly larvae oil (BSFLO) on growth performance, blood biochemicals, carcass quality, and metabolomics profile of breast muscle of Thai native chickens. A total of 192 1-day-old, mixed-sex, Pradu Hang Dam (Mor Kor 55) chickens were randomly allocated to one of three dietary groups. Each treatment had four replicates with 16 chicks per replicate (8 males and 8 females). Three dietary treatments were used: (T1) the control group, based on a corn-soybean meal with RBO, and two treatment groups that replaced 50% (T2) and 75% (T3) of RBO in the basal diet with BSFLO, respectively. Results showed that BSFLO inclusion at 50% and 75% did not adversely affect the productive performance of Thai native chickens (p > 0.05). Regarding blood profiles, on day 28, chickens fed 75% BSFLO exhibited significant increases in hemoglobin, hematocrit, and MCHC (mean corpuscular hemoglobin concentration) with lower eosinophil percentages compared to the control group (p < 0.05). Additionally, BSFLO supplementation raised glucose levels but decreased globulin and total protein levels (p < 0.05). On day 63, BSFLO inclusion primarily affected MCV (mean corpuscular volume), with higher values in the 50% BSFLO group (p < 0.05). It also increased globulin and HDL (high-density lipoprotein) levels while lowering AST (aspartate transaminase) concentrations (p < 0.05). For carcass and meat quality, BSFLO supplementation did not affect dressing percentage or edible meat yield (p > 0.05). However, it influenced meat pH and shear force (p < 0.05), with a higher pH at 24 h post-mortem in BSFLO-fed chickens. Metabolomics showed that arginine biosynthesis; phenylalanine, tyrosine, and tryptophan metabolism; alanine, aspartate, and glutamate metabolism; arginine and proline metabolism; and taurine and hypotaurine metabolism were the most differentially abundant. These findings suggest that BSFLO can be used for a partial replacement (50 to 75%) for RBO in Thai native chicken diets, potentially offering benefits for animal health and meat quality without compromising growth performance.

Estimation of the digestible energy value of fat obtained from black soldier fly larvae (Hermetia illucens) for growing pigs

An experiment was conducted to determine the digestible energy (DE) of insect fat (IF) from black soldier fly larvae (BSLF) for growing pigs. Saturated fatty acids (SFA) were the dominant group of fatty acids in the IF, with lauric acid (C12:0) and palmitic acid (C16:0) comprising the greatest concentrations in this group. Linoleic acids (C18:2) and oleic acids (C18:1) were the main unsaturated fatty acids. The IF contained 37.63 MJ/kg gross energy and 2.55 g/kg nitrogen. During the experiment, a DE bioassay was performed wherein growing pigs were fed one of the two experimental diets (either a maize-wheat-barley-soy basal diet or a diet containing 50 g/kg IF plus 950 g/kg of the basal diet). The DE of the IF was calculated based on the differences between the DE values of basal and test diet (substitution method). The DE of the IF was determined to be 36.86 MJ/kg. The IF contains a DE level comparable to vegetable oils, including soybean, rapeseed, corn and palm oils. The results showed that the examined fat from BSLF is a good source of available energy and can be incorporated in pig diets as an alternative energy source.

Insect live larvae as a new nutritional model in duck: effects on gut health

BACKGROUND

This study aimed to evaluate the effects of Hermetia illucens (Black soldier fly-BSF) and Tenebrio molitor (Yellow mealworm-YMW) live larvae as a new nutritional model on duck's gut health, considering gut histomorphometry, mucin composition, cytokines transcription levels, and microbiota. A total of 126, 3-days-old, females Muscovy ducks were randomly allotted to three dietary treatments (6 replicates/treatment, 7 birds/pen): (i) C: basal diet; (ii) BSF: C + BSF live larvae; (iii) YMW: C + YMW live larvae. BSF and YMW live larvae were administered on top of the basal diet, based on the 5% of the expected daily feed intake. The live weight, average daily gain, average daily feed intake and feed conversion ratio were evaluated for the whole experimental period. On day 52, 12 ducks/treatment (2 birds/replicate) were slaughtered and samples of duodenum, jejunum, ileum, spleen, liver, thymus and bursa of Fabricius were collected for histomorphometry. Mucin composition was evaluated in the small intestine through histochemical staining while jejunal MUC-2 and cytokines transcription levels were evaluated by rt-qPCR. Cecal microbiota was also analyzed by means of 16 S rRNA gene sequencing.

RESULTS

Birds' growth performance and histomorphometry were not influenced by diet, with a proximo-distal decreasing gradient from duodenum to ileum (p < 0.001), respecting the physiological gut development. Mucin staining intensity and MUC-2 gene expression did not vary among dietary treatments, even though mucin intensity increased from duodenum to ileum, according to normal gut mucus physiology (p < 0.001). Regarding local immune response, IL-6 was higher in YMW group when compared to the other groups (p = 0.009). Insect live larvae did not affect cecal microbiota diversity, but BSF and YMW groups showed a higher presence of Helicobacter, Elusimicrobium, and Succinatimonas and a lower abundance of Coriobacteriaceae and Phascolarctobacterium compared to C birds (p < 0.05).

CONCLUSIONS

The use of BSF and YMW live larvae as new nutritional model did not impair gut development and mucin composition of Muscovy ducks, but slightly improved the intestinal immune status and the microbiota composition by enhancing regulatory cytokine IL-6 and by increasing minor Operational Taxonomic Units (OTUs) involved in short-chain fatty acids production.

Dietary and Therapeutic Benefits of Edible Insects: A Global Perspective

Edible insects are gaining traction worldwide for research and development. This review synthesizes a large and well-established body of research literature on the high nutritional value and variety of pharmacological properties of edible insects. Positive benefits of insect-derived products include immune enhancement; gastrointestinal protection; antitumor, antioxidant, and anti-inflammatory capacities; antibacterial activities; blood lipid and glucose regulation; lowering of blood pressure; and decreased risk of cardiovascular diseases. However, the pharmacological mechanisms of these active components of edible insects in humans have received limited research attention. In addition, we discuss health risks (safety); application prospects; regulations and policies governing their production and consumption with a view to promote innovations, intraglobal trade, and economic development; and suggestions for future directions for further pharmacological functional studies. The aim is to review the current state of knowledge and research trends on edible insects as functional ingredients beneficial to the nutrition and health of humans and animals (livestock, aquatic species, and pets).

Black Soldier Fly Larva Fat in Broiler Chicken Diets Affects Breast Meat Quality

This study aimed to evaluate the dose-dependent effect of black soldier fly (BFL) larvae fat inclusion in broiler chicken diets on breast meat quality. Four hundred 1-day-old male birds (Ross 308) were assigned to the following four treatments (10 replicates with 10 birds each): HI0, a basal diet without dietary fat inclusion, and HI03, HI06, and HI09, basal diets enriched with 30 g/kg, 60 g/kg, and 90 g/kg of BSF larvae fat, respectively. Principal component analysis showed noticeable differentiation between the selected plant, animal, and insect-origin dietary fats. The BSF fat exhibits a strong relationship with saturated fatty acids (SFAs), resulting in a high concentration of C12:0 and C14:0. The fatty acid (FA) profile in breast muscle obtained from broilers fed diets with increasing insect fat inclusion showed a significant linear effect in terms of C12:0, C15:0, C18:2, C18:3n6, and total FAs. The proportion of dietary insect fat had a quadratic effect on meat color. The water-holding capacity indices have stayed consistent with the meat color changes. Throughout the experiment, favorable growth performance results were noticed in HI06. The present study confirmed that BSF larvae fat negatively affects the n3 level in meat. However, the physicochemical indices related to consumer acceptance were not altered to negatively limit their final decision, even when a relatively high inclusion of insect fat was used.

Dietary supplementation with full-fat Hermetia illucens larvae and multi-probiotics, as a substitute for antibiotics, improves the growth performance, gut health, and antioxidative capacity of weaned pigs

BACKGROUND

Dietary supplementation of full-fat black soldier fly larvae (BSFL full-fat meal; alone or in combination with multi-probiotics) was tested as an alternative to dietary antibiotics in weaning piglets. We also tested the effects of these diets on growth performance, nutrient digestibility coefficients, immune status, oxidative stress, intestinal histomorphology, and rectal microbial modulations in weaned pigs. A total of 80 piglets [(Landrace × Large White) × Duroc] of both sexes (a ratio of gilts and barrows; 1:1), were randomly allotted to four diet groups: positive control (PC) diet supplemented with 0.02% amoxicillin; negative control (NC) diet without supplement addition; BSFL12 diet (NC + 12% BSFL full-fat meal); and BSFL + Pro diet (BSFL full-fat meal + 0.1% multi-probiotics, including Bacillus subtilis, B. licheniformis, and Saccharomyces cerevisiae). All groups had five replicates, with four piglets per replicate.

RESULTS

Dietary BSFL + Pro improved the overall average daily gain (P = 0.013), and gain-to-feed ratio (P = 0.032). The BSFL12 and BSFL + Pro diets improved nutrient digestibility and increased the serum levels of immunoglobulin A and glutathione peroxidase, while reducing the levels of pro-inflammatory cytokines. The spleen weight was higher and caecal pH was lower in pigs fed the BSFL + Pro diet than in those fed the NC diet (P = 0.011 and P = 0.021, respectively). Pigs fed the BSFL diets had longer duodenal villi, a higher villus height-to-crypt depth ratio (P = 0.004), and shorter crypt depth (P = 0.017) than those fed NC. The BSFL + Pro diet also increased faecal Lactobacillus spp. count (P = 0.008) and reduced Escherichia coli (P = 0.021) counts compared with that seen with PC and NC diets, respectively.

CONCLUSIONS

Dietary supplementation with BSFL or BSFL + multi-probiotics can improve the growth performance and intestinal health of pigs and may be an effective strategy to replace antibiotics for weaned pigs.