May 4, 2018

Papers regarding use of BSF larvae in animal feed

Scientific papers regarding use of black soldier fly larvae in animal feed:

Insects are promising feedstuffs for animal feeds as they contain not only valuable nutrients but also particular compounds that seem to be able to modulate animal microbiota and to optimise animal health. So far, there has been little work on the effects of those insect derived compounds in animal feeding trails but initial investigations show promising results. This editorial discuss the effect of chitin, lauric acid, and anti-microbial peptides provided by insects.

Black soldier fly (Hermetia illucens) larvae (BSFL) are rich in protein and have the potential to be used in animal feed. The aim of the present study was to determine the immunoprophylactic effect of BSFL against Salmonella Gallinarum in broiler chicks as an alternative feed additive. Results showed that BSFL improved body weight gain and increased frequency of CD4+ T lymphocyte, serum lysozyme activity, and spleen lymphocyte proliferation. Moreover, BSFL reinforced bacterial clearance and increased survivability of broiler chicks against S. Gallinarum. These data suggested that BSFL has prophylactic properties with stimulating non-specific immune responses, as well as reduced bacterial burden against S. Gallinarum.

Insects could be potential nutritional sources both for humans and animals. Among these, Hermetia illucens, with good amount of chitin and proteins, represents a suitable diet replacement for laying hens. Little is known about insect diet effects on the microbial ecology of the gastrointestinal tract and bacterial metabolites production. In this study we investigated the effect of H. illucens larvae meal administration on cecal microbiota and short chain fatty acids (SCFAs) production in laying hens. 16S rDNA sequencing showed strong differences between cecal microbiota of soybean (SD) and insect diet (ID) groups both in type and relative abundance (unweighted and weighted beta diversity) of microbial species. In particular, Bacteroides plebeius, Elusimicrobium minutum, Alkaliphilus transvaalensis, Christensenella minuta, Vallitalea guaymasensis and Flavonifractor plautii represented the principal contributors of changes in gut microbiota composition of ID group (FDR p-values < 0.05). Of these, F. plautii, C. minuta and A. transvaalensis have the potential to degrade the chitin’s insect meal and
correlated with the observed high levels of gut SCFAs produced in ID group. These microorganisms may thus connect the chitin degradation with high SCFAs production. Our results suggest H. illucens as a potential prebiotic by well feeding gut microbiota.

The present research studied for the first time the potential application of the fat derived from the black soldier fly larvae fat (BSLF) in substitution to the soybean oil in the diet for broiler chickens: growth performances, feed-choice, blood traits, carcass characteristics and meat quality were considered in this study. A total of 150 male broiler chicks (Ross 308) at one-day of age were randomly allotted to 3 dietary treatments (5 replicates and 10 birds/pen): a basal control diet (C group), and the same diet in which the soybean oil was replaced by 50% (CH group) or 100% (H group) BSLF. Growth performances, feed-choice test, blood traits and slaughtering performances were not influenced by diets. Independently of BSLF inclusion, broiler chickens breast meat had also similar crude protein and ether extract contents and displayed similar thawing loss. Furthermore, pH, L, a, b colour values, and drip loss were unaffected by dietary treatments
both at 0 and 9 days of refrigerated storage. As expected, the fatty acid profile of broiler chickens breast was greatly affected by BSLF inclusion level. With increasing BSLF inclusion rate, the proportion of SFA increased (32.2, 37.8, 43.5% for C, CH and H breast meat, respectively, p<.001) to the detriment of the PUFA fraction (22.7, 23.0, 22.9% for C, CH and H breast meat, respectively, p<.001). On the contrary, MUFA fraction was unaffected. BSLF inclusion guaranteed satisfactory productive performances, carcass traits and overall meat quality, thus suggesting that BSLF could be a promising new feed ingredient for chickens.

The study aimed to determine the apparent total tract digestibility coefficients (ATTDC) of nutrients, the apparent metabolizable energy (AME and AMEn) and the amino acid (AA) apparent ileal digestibility coefficients (AIDC) of a partially defatted (BSFp) and a highly defatted (BSFh) black soldier fly larvae meal. The experimental diets were: a basal diet and two diets prepared by substituting 250 g/kg (w/w) of the basal diet with BSFp or BSFh, respectively. Significant differences were found between BSFp and BSFh meals for ATTDC of the nutrients: BSFp resulted more digestible than BSFh, except for ATTDC of CP which did not differed between meals, while a statistical trend was observed for ATTDC of DM and EE. The AME and AMEn values were significantly (P < 0.05) different between the two BSF meals, with higher levels for BSFp (16.25 and 14.87 MJ/kg DM, respectively). The AIDC of the AA in BSFp ranged from 0.44 to 0.92, while in BSFh they ranged from 0.45 to 0.99. No significant differences were observed for the AA digestibility (0.77 and 0.80 for BSFp and BSFh, respectively), except for glutamic acid, proline and serine that were more digestible in the BSFh meal (P < 0.05). Defatted BSF meals can be considered as an excellent source of AME and digestible AA for broilers with a better efficient nutrient digestion. These considerations suggested the effective utilization of defatted BSF larvae meal in poultry feed formulation.

PROteINSECT project’s key publication recommends review of insect protein legislation & funding to help address European protein deficit
– PROteINSECT fish feeding trials demonstrated insect meal can replace up to 50% of feed without affecting animal performance
– PROteINSECT pig feeding trials revealed improved gut health in piglets
– PROteINSECT poultry feeding trials showed that chickens fed on insectcontaining diets performed as well as those fed on commercial diets

Insect protein is becoming an increased area of interest because of the potential positive effects that it may have in animal feeds. Insect protein is believed to have beneficial nutritional components desirable for livestock while reducing the amount of environmental pollution due to their ability to be reared on bio-waste streams. Soya meal and fishmeal are the most commonly used protein sources in livestock diets.
However, due to competition with human consumption and bio-fuel utilisation of soya and decreasing fish stocks for the production of fishmeal (making both these raw materials unsustainable), alternative protein sources in the form of insects are being investigated.

The black soldier fly (BSF) (Hermetia illucens) is regarded as the insect with the highest potential for waste recycling. There is limited research of the use of black soldier fly larvae (BSFL) incorporated into layer hen diets. In this investigation, BSFL were processed with three different techniques: a full fat, dry rendered and an extruded meal. All three treatments were incorporated into three different layer diets at 15% inclusion levels. The diets were fed to layer hens for a period of 41 days and compared to a control maize soya diet.

Positive results as pertaining to production and egg quality parameters were found. The full fat and extruded meal had the highest egg lay percentage (amount of eggs laid throughout the duration of the trial per treatment) and differed (P≤0.05) from the control diet. No differences between treatments were found with regard to categorical data which included blood and meat spots, albumin spread and yolk colour and yolk membrane. With regard to egg quality parameters, a difference (P≤0.05) was found between the albumin weights. All three insect meals differed from the control diet with heavier albumin weights.

The results obtained in this study are in favour of the use of black solider fly larvae processed using any of the three techniques in poultry feeds.

A 59-days feeding trial was carried out to estimate the effects of fish meal replacement by defatted black soldier fly larvae meal (DBSFLM) on growth performance, antioxidate enzyme activities , digestive enzyme activities, hepatopancreas and intestinal morphology in Jian carp (Cyprinus carpio var. Jian) juveniles (initial mean body weight, 34.78 g). Five isolipidic (5.29±0.04%) and isoprotein (40.69±0.11%) diets were formulated by replacing 0%, 25%, 50%, 75%, 100% fish meal (FM) protein with graded DBSFLM levels of 0%, 2.6%, 5.3%, 7.9% and 10.6%. Each diet was randomly assigned to triplicate groups of 20 fish per aquarium. Fish were fed three times daily to apparent satiation. The results showed that the growth performance and nutrients utilization of fish in five groups were not different (P>0.05). The  epatopancreas lipid and serum cholesterol content of treated groups was significantly lower than that of the control group (P<0.05). With increasing dietary DBSFLM level, the activity of the CAT significantly increased. No significant  differences in the activity of intestinal protease, lipase and diastase were observed among dietary groups (P>0.05). The histological examination of intestine showed that when 75% or more FM protein was replaced, apparent pathological changes for example tissue disruption were observed in intestine, and relative gene expression of HSP70 in hepatopancreas significantly increased (P<0.05). The histological examination of hepatopancreas sections showed less vacuolated with lipid deposits in treatment groups compared with control group. These results suggested that the growth of Jian carp was not affected by dietary DBSFLM, while it boosted antioxidant status of Jian carp by higher CAT activity. However, dietary stress and intestinal histopathological damage was observed when the replacement levels exceeded 75%. The study demonstrates that it is suitable to replace up to 50% of dietary FM protein with DBSFLM.