True metabolizable energy and amino acid digestibility in black soldier fly larvae meals, cricket meal, and mealworms using a precision-fed rooster assay

Regulation of serum reproductive hormones, gap junction proteins, and cytokine profiles in laying hens fed varying levels of expanded black soldier fly meal

This study examined the impact of expanded black soldier fly (EP-BSF) meal on laying hens' reproductive hormones, gap junction proteins, cytokines, and performance. Over the 12 weeks trail period, 400 Hy-Line brown hens procured at 24 weeks of age underwent a completely randomized design with 5 treatments, 8 replicates, and 10 birds per replicate. The hens received a control diet (CON) or diets with 3 %, 6 %, 9 %, or 12 % EP-BSF. Results demonstrated that lower EP-BSF levels showed a linearly higher (p < 0.05) hen day egg production (HDEP) from 30 to 33 weeks and a linearly higher (p < 0.05) egg mass (EM) in the cumulative weeks comparable to CON. Tendencies towards a linearly higher average egg weight (AEW) was observed when EP-BSF was incorporated at lower levels comparable to CON during 34-37 weeks (p = 0.079), as well as in the cumulative weeks (p = 0.056). Yolk color was quadratically higher (p < 0.024) during 30-33 weeks, with higher tendency (p = 0.050) in the cumulative weeks as the EP-BSF level increases. Albumin weight was linearly higher (p < 0.05) at lower EP-BSF supplementation level comparable to CON at 26-29 weeks and at the cumulative weeks, with linearly higher tendency (p = 0.062) at 34-37 weeks. Eggshell thickness was quadratically increased (p < 0.05) at 30-33 weeks, with a quadratically higher tendency (p = 0.050) during the cumulative weeks as the level of EP-BSF increased. Serum estradiol (E2) levels were linearly increased (p < 0.05) in the lower EP-BSF groups, correlating with increased expression of connexins GJA1 and GJA4 in oviductal tissues and lower tumor necrosis factor-alpha (TNF-α). In conclusion, the incorporation of lower levels of EP-BSF had similar HDEP, AEW, EM, and albumin weight as CON. We attributed this to the increased E2 levels resulting in lower TNF-α, and higher expression of GJA and GJA4 in the chicken oviduct. Our findings also strongly indicate estrogen plays a role in modulating the expression of connexins. These findings suggest that lower EP-BSF in layer diet may serve as an alternative protein source for poultry feed.

Partial Replacement of Soyabean Meal with Defatted Black Soldier Fly (Hermetia illucens L.) Larvae Meal Influences Blood Biochemistry and Modulate Oxidative Stress, but Not Growth Performance of Pigs

The production of soybean meal (SBM) can be linked to various issues related to the environment (e.g., deforestation, water waste, and transportation costs), and reducing its inclusion in pig diets by using alternative protein sources, such as insect meal, is an important challenge for nutritionists. This study aimed to compare the productive performance, dietary digestible energy (DE), nutrient digestibility, and some blood indices of growing Danube White pigs fed graded levels of Black Soldier fly (Hermetia illucens L.) larvae meal (BSFLM) at 0, 30, 60, 90, and 120 g/kg of diets, in replacement of SBM for 38 days, from 119 to 157 d old. Each diet was fed to eight pigs in individual boxes following randomization. Pigs grew according to breeders' recommendations and did not have any clinical health problems. Replacing SBM did not change (p > 0.05) the pigs' growth performance and DE, as only dietary fat digestibility increased in a linear fashion (p < 0.001), possibly due to the high BSFLM, i.e., the high-fat inclusion rate. There was a simultaneous rise in some oxidative damage indicators and an increase in antioxidant status, thus suggesting that further research involving longer feeding periods is needed to identify a potential time sequence of events. Overall, BSFLM is a promising ingredient in pig nutrition.

Poultry Nutrition: Achievement, Challenge, and Strategy

Poultry, a vital economic animal, provide a high-quality protein source for human nutrition. Over the past decade, the poultry industry has witnessed substantial achievements in breeding, precision feeding, and welfare farming. However, there are still many challenges restricting the sustainable development of the poultry industry. First, overly focused breeding strategies on production performance have been shown to induce metabolic diseases in poultry. Second, a lack of robust methods for assessing the nutritional requirements poses a challenge to the practical implementation of precision feeding. Third, antibiotic alternatives and feed safety management remain pressing concerns within the poultry industry. Lastly, environmental pollution and inadequate welfare management in farming have a negative effect on poultry health. Despite numerous proposed strategies and innovative approaches, each faces its own set of strengths and limitations. In this review, we aim to provide a comprehensive understanding of the poultry industry over the past decade, by examining its achievements, challenges, and strategies, to guide its future direction.

Effect of Different Dietary Doses of Black Soldier Fly Meal on Performance and Egg Quality in Free-Range Reared Laying Hens

(1) Background: Given the problems currently posed by the use of soybean meal in poultry feeding, its replacement with black soldier fly (BSF) meal may be a suitable strategy. Therefore, this study evaluated the effect of this dietary replacement on laying performance, egg quality, and yolk nutritional composition in free-range reared hens. (2) Methods: Three diets were formulated: a control diet with 210 g/kg of soybean meal, a diet with 105 g/kg of soybean meal and 80 g/kg of BSF meal, and a diet with 160 g/kg of BSF meal. This eight-week-long study was performed with 126 Bovans Brown hens aged 36 weeks (six replicates of seven hens each per dietary treatment); (3) Results: The laying performance of hens was not influenced by the diet consumed. Neither was the yolk content in fat, protein, cholesterol, choline, B vitamins, and cholecalciferol affected. The dietary inclusion of BSF meal made yolk colour score and albumen Haugh units decrease (p < 0.001) by 51.1% and 12.0%, respectively. It also reduced the yolk content in retinol (by 10.1%, p = 0.0037), but it increased that of α- and γ-tocopherol (by 27.6%, p = 0.014, and 25.8%, p = 0.0077, respectively). A negative linear effect (p < 0.001) was observed on yolk zinc concentration and on the proportions of polyunsaturated and ω-3 fatty acids with increasing dietary dose of BSF meal; (4) Conclusions: Soybean meal could be fully replaced by BSF meal in the diet of hens without affecting the laying rate or the egg weight. However, the dietary inclusion of BSF meal led to paler yolks and impaired albumen quality, while it decreased the content of retinol and zinc and the proportions of polyunsaturated and ω-3 fatty acids in egg yolk.

Nutritional Value of the Larvae of the Black Soldier Fly (Hermetia illucens) and the House Fly (Musca domestica) as a Food Alternative for Farm Animals-A Systematic Review

Dietary alternatives using insect-based products as an alternative for farm animal nutrition have been the object of study due to the high nutritional value of these feeds and the costs related to both their production and consequently their commercialization. Thus, the use of flies, especially larvae, has a high content of proteins and lipids (fat), as well as minerals and essential nutrients for development and growth, directly impacting the production of these animals, whether meat or milk. Therefore, the objective of this study was to compile data from the literature on the nutritional value of adults and larvae of Black soldier (Hermetia illucens) and housefly (Musca domestica) as a dietary alternative for animal feed. The Prisma checklist was used. After reviewing the data found in the literature, following the systematic review, it was noted that studies emerge that larvae of black soldier flies and domestic flies of the order Diptera obtain essential sources in the nutrition of ruminants, in addition to obtaining rapid digestibility, thus adhering to reproduction with high nutritional content, due to incident levels of protein, lipids, and minerals in M. domestica and Lucilia sericata, making it a target for inclusion in the diet of farm animals. In addition, it is concluded that both species are studied for their sustainable potential as well as for offering greater economic and nutritional viability when compared to ingredients present in production animal feed.

A metanalysis to evaluate the effects of substrate sources on the nutritional performance of black soldier fly larvae: implications for sustainable poultry feed

This meta-analysis presents an evaluation of substrate sources and their impact on the growth performance of black soldier fly (BSF) larva. The database, compiled from Google Scholar, PubMed, and Science Direct, focuses on data concerning substrate sources, environmental conditions, and the performance parameters of BSF. Seven types of substrates were analyzed, including Feed Waste, Manure, Fruits, Mix, Animal Source, Fermentation Residue, and Food Waste. The Feed Waste group demonstrated the highest DM content, while the highest CP content was found in the Animal Source group. Higher CP and DM content were found in larva meal from Fermentation Residues and Feed Waste diets, respectively. Higher survival rates were observed in BSF larvae fed on Feed Waste, Fermentation Residues, Food Waste, Fruits, Mix, and Manure substrates compared to Vegetable and Animal Source substrates. Fresh larval weight was lower when Manure was used as a feed substrate than in the Animal Source, Feed Waste, and Vegetable substrates. The prepupal Wet Weight was highest in BSF larvae fed on Animal Source, surpassing those fed on Fermentation Residue, Manure, and Vegetable substrates. Substrate CP content exhibited a positive relationship with fresh larva weight, prepupal wet weight, dry larval weight; larval length, mortality until prepupal, protein conversion, feed conversion ratio, food consumption, substrate reduction rate bioconversion ratio, waste reduction index, and efficiency conversion of digested feed in BSF larva. In conclusion, our findings underline that the source and composition of substrates are correlated to the nutritional composition and conversion efficiency of BSF larva meal.

Amino acid digestibility of insect meals and effects on key bacterial groups in excreta of caecectomised laying hens

The chemical composition and amino acids (AA) digestibility were determined in insect meals from mealworms, crickets, black soldier fly (BSF) larvae and BSF prepupae, and soybean meal. Six caecectomised laying hens were individually housed in metabolism cages and fed either a basal diet or one of five assay diets. Diets and hens were arranged in a 6 × 6 Latin square design with 6 subsequent periods. In each period, the laying hens were fed their respective diet for 9 d, and excreta samples were quantitatively collected twice daily from day 5 to 8. On day 9, a sterile plastic bag was attached to the cloaca of each hen to collect excreta for microbiota analysis. The AA digestibility of the insect meals and soybean meal were calculated using a linear regression approach. Crude protein (CP) concentrations in crickets and mealworms were higher than the value in soybean meal, BSF prepupae and BSF larvae. Ether extract concentrations were high in the insect meals and low in the soybean meal. The digestibility of most essential AA in soybean meal was higher (p < 0.05) than in crickets and BSF prepupae and not different from AA digestibility in mealworms and BSF larvae (except for arginine and histidine). The gene copy number of Escherichia coli in excreta from hens fed with BSF prepupae was lower (p < 0.05) than those fed with BSF larvae, whereas the gene copy number of Bacillus spp. and Clostridium spp. in excreta from hens fed with crickets was lower (p < 0.05) than those fed with BSF larvae. In conclusion, the chemical composition and AA digestibility varied among insect meals based on insect species and life stage. The high level of AA digestibility of insect meals supports the assessment that insect meals are a suitable feed component for laying hens, but differences in AA digestibility should be considered in diet formulation.

The apparent metabolisable energy and ileal amino digestibility of black soldier fly (Hermetia illucens) larvae meal for broiler chickens

1. Two experiments were conducted to determine the apparent metabolisable energy (AME) and standardised amino acid digestibility coefficients (SIDC) of black soldier fly larvae (BSFL) for broiler chickens.2. The BSFL contained, on a g/kg dry matter basis: crude protein, 486; crude fat, 320; ash, 58.5; neutral detergent fibre, 181; calcium, 6.8 and phosphorus, 9.1.3. In Experiment 1, an AME assay was performed wherein broilers were fed two experimental diets (a maize-soy basal diet and a test diet containing 250 g/kg BSFL) for 4 d from d 18 posthatch. The AME of BSFL was calculated based on the difference between the AME values of basal and test diets. The AME and nitrogen-corrected AME were determined to be 19.1and 18.0 MJ/kg of dry matter, respectively.4. In Experiment 2, the ileal amino acid (AA) digestibility of BSFL was determined using 22-d-old broilers by the direct method and the digesta was collected on d 25. The ratios between the AA and titanium in the diet and digesta were used to calculate the apparent digestibility and then standardised using previously published endogenous losses to estimate the SIDC of AA. The SIDC of Lys, Met, Thr, Val and average SIDC of AA in our BSFL sample were 0.85, 0.90, 0.91, 0.87 and 0.84, respectively.5. The findings showed that the BSFL meal is a good source of available energy and digestible AA, and could be a potential substitute for soybean meal in broiler diets.

Amino acid digestibility and protein quality of mealworm-based ingredients using the precision-fed cecectomized rooster assay

Mealworms may serve as an alternative protein source for pet foods because of their high protein content and low environmental footprint. The amino acid (AA) content and protein quality of mealworm-based ingredients may vary depending on their composition and processing, however, so testing is required. Our objective was to measure the AA composition, AA digestibility, and protein quality of mealworm-based ingredients using the precision-fed cecectomized rooster assay. The University of Illinois Institutional Animal Care and Use Committee approved all animal procedures prior to experimentation. Sixteen cecectomized roosters (4 roosters per substrate) were randomly allotted to one of four test substrates: 1) whole lesser mealworm (A. diaperinus) meal (ADw); 2) defatted lesser mealworm (A. diaperinus) meal (ADd); 3) defatted yellow mealworm (T. molitor) meal (TMd); and 4) hydrolyzed T. molitor protein meal (TMh). Ingredients were provided by Ÿnsect, France. After 26 h of feed withdrawal, roosters were tube-fed test substrates. Following crop intubation, excreta samples were collected for 48 h. Endogenous loss corrections for AA were made by using five additional cecectomized roosters. All data were analyzed using SAS version 9.4. All substrates had high AA digestibilities, with all indispensable AA digestibilities being >90% with the exception of histidine (87.9% to 91.1%) and valine (77.9% to 79.7%). Amino acid digestibilities were not different among substrates (P > 0.05). Digestible indispensable AA score (DIAAS)-like values were calculated to determine protein quality according to Association of American Feed Control Officials (AAFCO) nutrient profiles, The European Pet Food Industry Nutritional Guidelines (FEDIAF) nutritional guidelines, National Research Council (NRC) recommended allowances for adult dogs, adult cats, growing puppies, and growing kittens, and NRC minimal requirements for growing puppies and growing kittens. In general, TMh had the highest and TMd had the lowest DIAAS-like values for most indispensable AA. Methionine (TMh; TMd; ADw) and phenylalanine (ADd) were the first-limiting AA. Our results demonstrate that mealworm-based ingredients are high-quality protein sources. Further research in dogs and cats is necessary to confirm sufficient palatability and digestibility, but these data suggest that they are valuable sources of protein for pet foods.

Comparative protein quality in black soldier fly larvae meal vs. soybean meal and fish meal using classical protein efficiency ratio (PER) chick growth assay model

Black soldier fly larvae meal (BSFLM) is a relatively new ingredient that has attracted attention for application in human, farm, and companion animal nutrition. However, there is limited data on protein quality (PQ) of BSFLM. This study compared PQ in BSFLM with soybean meal (SBM) and fishmeal (FM) using the classical protein efficiency ratio (PER) chick growth assay model. A total of 240-male day-old Ross × Ross broiler chicks were allocated to 6 test diets for 10 d test. The corn starch-dextrose based diets were: 5 test diets containing 10% crude protein (CP) from casein (as a standard assay diet), SBM, FM, or BSFLM without or with (BSFLM+) additional essential amino acids (EAA) to match the levels of the SBM diet on digestible basis. A sixth diet was nitrogen-free (NFD), to enable calculation of net protein ratio (NPR). The birds had ad libitum access to feed and water, body weight (BW) and feed intake (FI) were recorded at the beginning and end of the experimental feeding period. Body weight gain (BWG), gain to feed ratio (G:F), crude protein intake (CPI), PER, and NPR were calculated. The analyzed CP (as fed) was 10.1, 12.8, 9.5, 11.7, and 14.9% for casein, SBM, FM, BSFLM, and BSFLM+ diets, respectively. Birds fed BSFLM+ had greater BWG (P < 0.01) than birds fed other diets. Feed intake was greater (P < 0.01) for birds fed BSFLM+ and FM diets than birds fed other diets. Birds fed BSFLM+ ate (P < 0.01) more CP than birds fed other diets. Diets had no (P > 0.05) effects on PER and NPR. In terms of ranking, the PER was 2.44, 2.38, 2.34, 2.28, and 2.10 g BWG/g CPI for BSFLM+, SBM, FM, casein, and BSLM, respectively. Corresponding values for NPR were 2.69, 2.78, 2.70, 2.74, and 2.48 g BWG/g CPI, respectively. In conclusion, the protein quality of BSFLM without or with additional EAA was comparable with FM and SBM.

Defatted silkworm pupae meal as an alternative protein source for cattle

Silkworm pupae meal (SWP) is a protein-rich by-product of the silk reeling industry, available in a significant quantity. However, there has been little and insignificant research into the use of SWP in ruminants to date. In this view, the present study was conducted in two phases to evaluate the effect of different inclusion levels of defatted silkworm pupae meal (DSWP) on rumen fermentation, microbial protein synthesis and nutrient utilisation in cattle fed on finger millet straw (FMS)-based diet. Four isonitrogenous concentrate mixtures (CM) were prepared with DSWP replacing soybean meal (SBM) protein at 0 (T0), 10 (T1), 20 (T2) and 30% (T3). In phase I, a rumen fermentation experiment was conducted in a 4 × 4 Latin square design using four crossbred steers to study the effect of different levels of DSWP on rumen fermentation. No significant difference (P > 0.05) was observed in rumen fermentation parameters such as pH, ammonia nitrogen (NH₃-N) and total volatile fatty acids (VFA) among the experimental groups. In phase II, the digestibility trial was conducted in 20 crossbred cattle (311.2 ± 4.81 kg), which were divided into four experimental groups of five animals each in a completely randomised design to study the effect of different rations (T0, T1, T2, T3) on microbial protein synthesis and nutrient utilisation. The intake and digestibility of nutrients, excretion of urinary purine derivatives and microbial protein synthesis were not significantly different among the experimental groups. In addition, feeding DSWP revealed no significant (P > 0.05) change in the blood biochemical parameters of animals. Furthermore, at the same price as SBM, DSWP provides two units more crude protein. Therefore, the results of the present study indicated that DSWP can be incorporated into the ration of cattle up to 30% by replacing SBM without affecting rumen fermentation pattern and nutrient utilisation.

Insects in Pet Food Industry-Hope or Threat?

Due to the increasing global population, the world cannot currently support the well-known techniques of food production due to their harmful effects on land use, water consumption, and greenhouse gas emissions. The key answer is a solution based on the use of edible insects. They have always been present in the diet of animals. They are characterized by a very good nutritional value (e.g., high protein content and contents of essential amino acids and fatty acids, including lauric acid), and products with them receive positive results in palatability tests. Despite the existing literature data on the benefits of the use of insects as a protein source, their acceptance by consumers and animal caregivers remains problematic. In spite of the many advantages of using insects in pet food, it is necessary to analyze the risk of adverse food reactions, including allergic reactions that may be caused by insect consumption. Other hazards relate to the contamination of insects. For example, they can be contaminated with anthropogenic factors during breeding, packaging, cooking, or feeding. These contaminants include the presence of bacteria, mold fungi, mycotoxins, and heavy metals. However, insects can be used in the pet food industry. This is supported by the evolutionary adaptation of their wild ancestors to the eating of insects in the natural environment. The chemical composition of insects also corresponds to the nutritional requirements of dogs. It should be borne in mind that diets containing insect and their effects on animals require careful analysis. The aim of this article is to discuss the nutritional value of insects and their possible applications in the nutrition of companion animals, especially dogs.

Age-dependent response to fasting during assessment of metabolizable energy and total tract digestibility in chicken

Fasting is typically used to empty the gastrointestinal tract (GIT) and assess feed metabolizable energy (ME). However, the effects of fasting on energy and nutrient utilization are not well understood. This study aimed to explore the difference in GIT emptying, energy and nutrient utilization of broilers and adult roosters fed corn-soybean meal-based diet upon fasting. In experiment 1, 7 cages of broilers/adult roosters were selected and fasted for 72 h, and excreta were collected from 12 h of fasting and analyzed every 12 h to explore GIT emptying. Results indicated the GIT emptying time of free-feeding broilers or adult roosters is 12 or 24 h, respectively. In experiment 2, 4 treatments were used that consisted of 2 ages of birds (25 d broilers and 30 wk adult roosters) and 2 feeding forms (fed ad libitum or fasted for 36 h before formal feeding). Excreta was collected during refeeding, and the total collection method (TCM) and the index method (IM) were used for data analysis. Compared to non-fasted group, fasting increased the total tract digestibility of ME, gross energy (GE), and ether extract (EE) (by 1.80, 3.50 and 18.56%, respectively, all P < 0.05) in broilers, but decreased the total tract digestibility of nitrogen by 8.10% (P < 0.05). Conversely, fasting increased total tract digestibility of nitrogen in adult roosters (−0.37% vs. 11.65%, P < 0.05). The comparative analysis found that total tract digestibility of nitrogen obtained by TCM was greater than the result calculated by IM (17.76 % vs. −0.37). Similarly, total tract digestibility of GE calculated by TCM was significantly higher than the value observed by IM (P < 0.05). However, the results of total tract digestibility of GE and nitrogen in broilers calculated by TCM were consistent with those obtained by IM. Overall, fasting increases total tract digestibility in broilers and total tract digestibility of nitrogen in adult roosters, respectively. Additionally, total tract digestibility calculated by TCM may be overestimated.

Nutritional composition of various insects and potential uses as alternative protein sources in animal diets -A review

The aim of the present investigation is to determine the nutritional composition of various insects and their potential uses as alternative protein sources in animal diets. The feeding industry is to develop a production system that uses accessible resources, such as feed resources, and concentrate on their potential impacts on production yield and nutritional quality. Invertebrate insects, such as black soldier flies, grasshopper mealworms, housefly larvae, and crickets, have been naturally as human food and as nonruminants and aqua culture while for ruminants are of limitations. Insects can be mass-produced, participating in a circular economy that minimizes or eliminates food- and feed-waste through bioconversion. Although the model for formula-scale production of insects as feed for domestic animals has been explored for a number of years, significant production and transformation of conventional protein resources remains to be deeply investigated. This review will focus on the nutritional composition of various insects and their potential uses as alternative protein sources, as well as their roles for potential use to promote and support sustainable animal production. Furthermore, nutritional compositions, such as high protein, lauric acid omega 6, and omega 3, and bioactive compounds, such as chitin, are of great potential use for animal feeding.

Effect of Graded Substitution of Soybean Meal by Hermetia illucens Larvae Meal on Animal Performance, Apparent Ileal Digestibility, Gut Histology and Microbial Metabolites of Broilers

Simple Summary

Soybean meal (SBM) constitutes the major protein source in European poultry production, meaning a high dependency on imports and a reduced sustainability of produced meat. To cope with this challenge, alternative protein sources are needed, and insects are considered as a novel, alternative protein source in broiler nutrition. The objective of the present study was to evaluate the replacement of 15 or 30% of crude protein (CP) from SBM with Hermetia illucens (HI) defatted larvae meal CP regarding broiler performance, carcass traits, apparent ileal CP and amino acid (AA) digestibility, intestinal morphology, and microbial metabolites. The data showed impaired performance and lower ileal CP and AA digestibility with 30% substitution of CP from SBM with HI larvae meal CP. However, lower substitution, i.e., 15% substitution of SBM CP with HI larvae meal, for broiler feeds seems possible without impairment in animal performance and digestion variables and should be pursued in the future.

Abstract

The usage of insects as an alternative protein source for broiler feeds may help to reduce the dependency on soybean meal (SBM) imports. Therefore, the present study aimed to evaluate the replacement of 15 (SL15) or 30% (SL30) of crude protein (CP) from SBM with Hermetia illucens (HI) defatted larvae meal regarding broiler performance, carcass traits, apparent ileal digestibility, intestinal morphology, and microbial metabolites. Concerning the performance, body weight was similar for the control (CON) and SL15, but lower for SL30 during all feeding phases. In addition, average daily feed intake was higher in SL15 and SL30 compared to CON in the starter phase, but this effect vanished during grower and finisher phase. The apparent ileal digestibility decreased for CP and some amino acids with increasing HI larvae meal in the diet. No or marginal alterations were observed for the intestinal morphometry as well as cecal microbial metabolites. In conclusion, partial replacement of 15% SBM CP with HI larvae meal in broiler diets without impairing animal performance or health seems possible. The growth suppression with 30% CP substitution may be caused by reduced apparent ileal digestibility but could not be clearly associated with adverse effects of hindgut fermentation or altered gut morphology.

Phosphorus digestibility and relative phosphorus bioavailability in two dried black soldier fly larvae meals and a defatted black soldier fly larvae meal in broiler chickens

Two chicken assays were conducted to determine P availability, using three different approaches, for 2 black soldier fly larvae meals (BSFL 1 and 3) and one partially-defatted BSFL. Experiment 1 was conducted to determine ileal P digestibility and total tract P retention. Three experimental diets containing a BSFL as the only source of P were fed to broiler chickens from 19 to 22 days of age. Each diet contained 0.25% total dietary P. Ileal digesta and excreta were collected on day 22. Ileal digestibility of P was 87%, 75%, and 88% for BSFL 1, BSFL 3, and partially-defatted BSFL, respectively. Total tract P retention was 87%, 73%, and 85% for BSFL 1, BSFL 3, and partially-defatted BSFL, respectively. The objective of experiment 2 was to determine the relative bioavailability of P in the 3 insect meals relative to KH₂PO₄ using a chicken bone ash bioassay. Chickens were fed one of nine dietary treatments from 8 to 22 days of age. These diets included a P-deficient cornstarch-dextrose-SBM based diet (0.14% nonphytate P) or that diet supplemented with 0.05% or 0.10% P from KH₂PO₄, 7% or 14% BSFL 1, 8%, or 16% BSFL 3, and 8% or 16% partially-defatted BSFL. The slope-ratio method using multiple regression for tibia ash regressed on supplemental P intake was used to calculate the relative bioavailability of P where values for BSFL 1, BSFL 3, and partially-defatted BSFL were 54%, 51%, and 57%, respectively, relative to KH₂PO₄. The results of this study indicated that availability of P in BSFL based on ileal P digestibility and total tract P retention values was high, whereas relative bioavailability values for P based on tibia ash were approximately 20 to 30 percentage units lower.