Evaluation of Yellow Mealworm Meal as a Protein Feedstuff in the Diet of Broiler Chicks

A meta-analysis of the meat physicochemical parameters of broiler chickens fed insect-based diet

A total of 23 studies were identified in a literature search performed in the Scopus, Science Direct and Google Scholar databases for meta-analysis. The criteria used include studies that were published from 2015 to 2023 and those reporting the effects of insect meal utilisation in poultry diets. Data on live weight (LW), carcass weight (CW), moisture, meat pH, lightness (L*), redness (a*), yellowness (b*), proximate composition (protein, fat and ash content) and shear force in broilers were subjected to OpenMEE software, and data were pooled using a random-effect model. Subgroup analysis and meta-regression were performed to ascertain the influence of dietary insect meals on the response of meat aspects and the source of heterogeneity, respectively, using the following moderators (insect species, dosage level, feeding duration and age at slaughter). The results indicated that dietary insect meal did not affect LW, CW, meat L*, pH, shear force, moisture, fat and ash content. In contrast, dietary insect meal increased the a* of the meat (standardised mean differences (SMDs) = 1.03; 95% confidence intervals (CIs) = 0.484-1.578; p ≤ 0.001), b* (SMD = 1.117; 95% CI = 0.334-1.90; p = 0.005), and meat protein content (SMD = 0.365; 95% CI = 0.031-0.7; p = 0.032). The subgroup analysis showed that insect meal dosage of ≤10% and age at slaughtered ≤35 days had improved the LW, CW and meat L*. In addition, the meat a*, protein and ash content were also influenced by insect species, dosage levels and age at slaughter. In conclusion, ≤10% of either Hermetia illucens or Tenebrio molitor can be included in broiler diets without compromising the LW, CW, meat pH, colour, shear force, moisture, fat and ash content in broilers. The study therefore indicated that insect meals have a bright future as an alternative protein source in poultry diets.

Substitution of soybean meal for yellow mealworm meal in the diet of slow-growing chickens provides comparable carcass traits and meat quality

1. This study investigated the effects of incorporating yellow mealworm (Tenebrio molitor) larval meal as a partial and/or complete substitute for soybean meal on carcass and meat quality in slow-growing chickens.2. A total of 256 one-day-old male broilers were randomly allocated to 1 of 32 experimental units distributed among four treatments (n = 8): the control treatment (C), where soybean (SB) meal was the protein source, and three experimental treatments, in which SB meal was replaced by Tenebrio molitor (TM) larval meal at levels of 50% (T1), 75% (T2) and 100% (T3), respectively. Three different feed phases (1-29; 29-57 and 57-92 d of age) were used for each treatment. All chickens were slaughtered at 92 d of age, with eight animals per treatment randomly selected to assess carcass and meat quality. Near-infrared reflectance spectroscopy (NIR) was used to classify meat quality.3. Carcass traits were not significantly different between treatments, except for head and thigh weight, which were higher in the control group (p < 0.01). In terms of physicochemical characteristics, treatment T2 showed less yellowness (p < 0.05), while water and cooking losses were lower in treatments T1 and T2 (p < 0.01). Meat from both T1 and T2 groups had lower shear forces (p < 0.01), higher moisture content (p < 0.01) and less protein (p < 0.05) compared to treatments C andT3. Birds fed T3 had the highest meat ash content (p < 0.01). Chickens consuming TM had higher monounsaturated fatty acid (MUFA) levels and lower polyunsaturated fatty acid (PUFA) and n-6 acidsPUFA (p < 0.01).4. Substitution of SB with TM is a protein alternative for slow-growing chickens that supports carcass and meat quality comparable to those fed a conventional diet.

Carcass traits and meat quality assessment of two slow-growing chicks strains fed Acheta domesticus larval meal

Presently, there has been a noticeable rise in the consumption of poultry meat within the general population, particularly focusing on poultry sourced from alternative rearing systems as opposed to intensive ones. This study evaluated the impact of incorporating house cricket (Acheta domesticus,AD) larvae meal into the diet of 2 slow-growing chicken strains on their carcass traits and meat quality. A total of 256 one-day-old male chicks were utilized, with 128 belonging to the Red (R) strain and 128 to the Naked Neck (NN) strain. Chicks from each strain were randomly assigned to 16 replicates of 8 chicks each. Eight replicates were allocated to 2 distinct treatments (n=64 chicks/treatment) based on the diet employed: the control treatments for the Red (R-C) and Naked Neck (NN-C) strains were fed soybean meal, while the other 2 treatments were fed AD meal (R-AD and NN-AD). Three different rations were used throughout the growth cycle of the animals, tailored to meet the nutritional needs of the birds. All chickens were slaughtered at 95 d of age, and eight chickens per treatment were randomly chosen to assess carcass traits and meat quality. Near-infrared reflectance spectroscopy (NIRS) was employed to classify meat based on the feed and the chick strain, achieving a correct discrimination of 100% of the samples. The carcass traits exhibited significant alterations due to the inclusion of insect larval meal in the diet, resulting in reduced values across all parameters for chickens consuming AD meal, irrespective of genotype. The pH and cooking losses were generally higher for chicks fed cricket meal, as occurred with moisture. However, protein content was lower in the meat of chicks consuming cricket meal. Fat content showed lower values for NN chickens. There were minimal differences in the fatty acid profile, with lower C18:3n-3 values for chickens fed cricket meal. Therefore, including Acheta domesticus meal in the diets of slow-growing chick strains is a viable alternative to replace soybean meal. It provides meat quality characteristics comparable to those obtained in conventional systems.

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.

A Systematic Review and Metanalysis on the Use of Hermetia illucens and Tenebrio molitor in Diets for Poultry

Insect meal as a protein source has been considered a sustainable way to feed animals. H. illucens and T. molitor larvae meal are considered high-protein sources for poultry, also presenting considerable amounts of fatty acids, vitamins, and minerals. However, other potential components in insect meal and insect oil have been more extensively studied in recent years. Chitin, lauric acid, and antimicrobial peptides can present antimicrobial and prebiotic functions, indicating that low levels of their inclusion in insect meal can beneficially affect broilers' health and immune responses. This systematic review was developed to study the impact of insect products on the health parameters of broilers, and a metanalysis was conducted to evaluate the effects on performance. A database was obtained based on a selection of manuscripts from January 2016 to January 2023, following the mentioned parameters. Both H. illucens and T. molitor meal or oil products had positive effects on poultry health status, especially on the ileal and cecal microbiota population, immune responses, and antimicrobial properties. The average daily gain was greater in broilers fed T. molitor meal compared to H. illucens meal (p = 0.002). The results suggest that low levels of insect meal are suitable for broilers, without resulting in negative effects on body weight gain and the feed conversion ratio, while the insect oil can totally replace soybean oil without negative impacts.

Could Insect Products Provide a Safe and Sustainable Feed Alternative for the Poultry Industry? A Comprehensive Review

The planet is home to more than 2000 species of edible insects, some of which have been consumed as food for many years. Recently, edible insect products have been gradually increasing in several countries, such as Italy and Egypt, as novel feed resources for humans and animals due to their availability, potential economic benefits, and high nutritive value. The insect industry can provide a new solution for livestock nutrition and offer many additional advantages, but there are obstacles to overcome, such as some nutritional organizations that forbid its usage. Nevertheless, previous research indicates that different insect species could be used safely as nutraceuticals in poultry farming to improve broiler growth performance (>3%) and layer egg production (>5%). Among these species, there are various products and extracts that can be used in poultry nutrition in a sustainable manner. This review provides an outline of insect composition, nutrient values, application in poultry feed, safety, and guidelines, and finally, the future perspectives of insects as an alternative feed source in poultry diets.

Insect biorefinery: A circular economy concept for biowaste conversion to value-added products

With rapid growing world population and increasing demand for natural resources, the production of sufficient food, feed for protein and fat sources and sustainable energy presents a food insecurity challenge globally. Insect biorefinery is a concept of using insect as a tool to convert biomass waste into energy and other beneficial products with concomitant remediation of the organic components. The exploitation of insects and its bioproducts have becoming more popular in recent years. This review article presents a summary of the current trend of insect-based industry and the potential organic wastes for insect bioconversion and biorefinery. Numerous biotechnological products obtained from insect biorefinery such as biofertilizer, animal feeds, edible foods, biopolymer, bioenzymes and biodiesel are discussed in the subsequent sections. Insect biorefinery serves as a promising sustainable approach for waste management while producing valuable bioproducts feasible to achieve circular bioeconomy.

Growth performance, welfare traits and meat characteristics of broilers fed diets partly replaced with whole Tenebrio molitor larvae

The role of insects in animal nutrition has been reconsidered during recent years, paving the way for an increasing market for edible insects. Their protein and amino acid balance make them a promising source of protein for replacing high value proteins. Yellow mealworm, Tenebrio molitor L. (TM; Coleoptera: Tenebrionidae) larvae, have shown positive effects on broiler performance in several research studies and have a strong potential as a sustainable alternative protein source for monogastric animals. This study aimed to assess the effect of replacing various ratios of basal diets with T. molitor larvae on broiler performance as well as on several meat and welfare characteristics. For the study, 120 one-day-old male chicks (Ross 308) were randomly allocated in 3 treatments and 4 replications (10 birds per pen). Birds of the control group (basal diet) were fed with typical commercial maize and soymeal-based rations in mash form. The other 2 groups were treated with the same diet, after replacing 5% and 10% with dried TM larvae, respectively. On d 35 (end of trial), meat samples were collected and analysed. Body weight, feed intake, body weight gain and feed conversion ratio during the periods of 1 to 10 d (starter period), 11 to 24 d (grower period), 25 to 35 d (finisher period) and 1 to 35 d (total period) were assessed. Pododermatitis, diarrhoea, feather score and litter conditions were also assessed during the trial. The results indicated that TM larvae inclusion in the broilers' diet positively affected body weight gain values, as well as the carcass yield, the meat composition and various welfare traits. Additionally, the dietary treatments with TM larvae favourably affected meat composition and colour parameters, whereas there were also some positive effects on lipid and protein oxidation. Saturated fatty acids were decreased by the dietary supplementation whereas the polyunsaturated fatty acids to SFA ratio increased. In general, the study showed that whole TM larvae addition can provide a promising alternative to soybean meal in the diet of broilers, demonstrating a positive impact on growth, welfare and meat characteristics.

Growth performance and intestinal morphometric features of broiler chickens fed on dietary inclusion of yellow mealworm (Tenebrio molitor) larvae powder

Background

Climate change and the lack of conventional feed ingredients have made edible insects a highly nutritious alternative to feed production. The use of insects as food may help solve socio‐economic and environmental problems around the world and be in line with the United Nations Sustainable Development Goals.

Objective

In this study, the growth performance and intestinal morphology of broiler chickens were evaluated under the influence of adding different levels of Tenebrio molitor larvae meal (TM meal) to their diets.

Methods

One hundred and eighty one‐day‐old broiler chickens were divided into three treatments and five replications (12 chickens/pen). The experimental diets included a control diet and treatments containing 2.5% and 5% TM meal, which were fed to birds in the starter (0–10 days) and grower (11–25 days) stages, and during the final period (26–42 days), all birds were fed a regular finisher diet.

Results

The results showed that the diet containing TM meal had no remarkable effect on the mortality rate and feed intake of broilers (p > 0.05). In the starter period, the addition of 2.5% TM meal to broilers’ diet increased body weight gain than the control group (p ≤ 0.05). Also, the use of 2.5% TM meal in the starter period showed a significant effect on reducing the feed conversion ratio, compared to the birds fed by the control diet (p ≤ 0.05). Besides, the height of the villus, the depth of the crypt and their ratio were not altered among the different treatments (p > 0.05).

Conclusions

Overall, it can be concluded that TM meal could improve growth performance in the starter period and had no negative effects on broilers' performance and intestinal morphology in all the periods of the experiment.

Insect meal as a feed ingredient for poultry

Shortage of protein feed resources is the major challenge to the world farm animal industry. Insects are known as an alternative protein source for poultry. A wide range of insects are available for use in poultry diets. Insect larvae thrive in manure, and organic waste, and produce antimicrobial peptides to protect themselves from microbial infections, and additionally these peptides might also be functional in poultry feed. The feed containing antimicrobial peptides can improve the growth performance, nutrient digestibility, intestinal health, and immune function in poultry. Insect meal contains a higher amount of essential amino acids compared to conventional feedstuffs. Black soldier fly, mealworm, housefly, cricket/Grasshopper/Locust (Orthoptera), silkworm, and earthworm are the commonly used insect meals in broiler and laying hen diets. This paper summarizes the nutrient profiles of the insect meals and reviews their efficacy when included in poultry diets. Due to the differences in insect meal products, and breeds of poultry, inconsistent results were noticed among studies. The main challenge for proper utilization, and the promising prospect of insect meal in poultry diet are also addressed in the paper. To fully exploit insect meal as an alternative protein resource, and exert their functional effects, modes of action need to be understood. With the emergence of more accurate and reliable studies, insect meals will undoubtedly play more important role in poultry feed industry.

Meat Quality Parameters of Boschveld Indigenous Chickens as Influenced by Dietary Yellow Mealworm Meal

An experiment was conducted to examine the effects of yellow mealworm larvae (Tenebrio molitor) meal inclusion in diets of indigenous chickens. A total of 160 mixed-sex indigenous Boschveld chickens were randomly divided into four categories: control soybean meal (SBM) and yellow mealworm with percentage levels of 5, 10 and 15 (TM5, TM10 and TM15, respectively). Five replicate pens per treatment were used, with eight birds per pen/replicate. On day 60, two birds from each replicate were slaughtered and eviscerated. Meat quality parameters were measured out on raw carcass and cooked breast meat. The carcass weight, breast weight and gizzard weight of the control group was higher (p < 0.05) than the treatment group (TM15). The cooking loss was lower (p < 0.05) in the SBM control group but higher in the TM15 group. Colour characteristics of breast meat before cooking was lighter in the TM10 and TM15 group, ranged from 61.7 to 69.3 for L* and was significant (p < 0.05). The TM10 and TM15 groups showed a lighter colour than the SBM and TM5 groups. The breast meat pH taken after slaughter was different (p < 0.05) in TM5 and TM15, with the highest reading (pH 6.0) in the TM5 group. In conclusion, our experiment indicated that dietary Tenebrio molitor in growing Boschveld indigenous chickens’ diets could be considered a promising protein source for Boschveld indigenous chickens.

Tenebrio molitor as a source of interesting natural compounds, their recovery processes, biological effects, and safety aspects

Nowadays, it is urgent to produce in larger quantities and more sustainably to reduce the gap between food supply and demand. In a circular bioeconomy vision, insects receive great attention as a sustainable alternative to satisfy food and nutritional needs. Among all insects, Tenebrio molitor (TM) is the first insect approved by the European Food Safety Authority as a novel food in specific conditions and uses, testifying its growing relevance and potential. This review holistically presents the possible role of TM in the sustainable and circular solution to the growing needs for food and nutrients. We analyze all high value-added products obtained from TM (powders and extracts, oils and fatty acids, proteins and peptides, and chitin and chitosan), their recovery processes (evaluating the best ones in technical and environmental terms), their nutritional and economical values, and their biological effects. Safety aspects are also mentioned. TM potential is undoubted, but some aspects still need to be discussed, including the health effects of substances and microorganisms in its body, the optimal production conditions (that affect product quality and safety), and TM capacity to convert by-products into new products. Environmental, economic, social, and market feasibility studies are also required to analyze the new value chains. Finally, to unlock the enormous potential of edible insects as a source of nutritious and sustainable food, it will be necessary to overcome the cultural, psychological, and regulatory barriers still present in Western countries.

Mealworm (Tenebrio molitor)-derived protein supplementation attenuates skeletal muscle atrophy in hindlimb casting immobilized rats

This study aimed to investigate the effect of mealworm (Tenebrio molitor) derived protein supplementation on skeletal muscle atrophy of hindlimb casted immobilized rats. Twenty-four six-week-old male Sprague-Dawley rats were randomly divided into three groups: control sedentary group (CD, n = 8), control diet casting group (CDC, n = 8), and the mealworm-derived protein supplemented casting group (MDC, n = 8). CD and CDC group was supplemented AIN-76G diet and mealworm-derived protein supplemented diet for MDC group was substituted as 5% casein protein to 5% mealworm protein for 5 weeks and left hindlimb casting immobilization using casting tape for CDC and MDC group was done 1 week before sacrifice. After 5 weeks of mealworm supplementation, the soleus muscle weight of the MDC group was significantly higher compared to the CDC group. In addition, the level of muscle protein synthesis factors p-Akt/Akt, p-4EBP1/4EBP1, and p-S6K/S6K significantly increased in the MDC group compared to the CDC group. On contrary, the level of muscle protein degradation factors (MuRF1 and atrogin-1) was significantly lower in the MDC group than that of the CDC group. These results suggest that mealworm-derived protein supplementation may have a significant role in the prevention of skeletal muscle atrophy via stimulation of muscle protein synthesis factors and inhibition of muscle protein degradation factors, and therefore a promising intervention in sarcopenia.

The effect of yellow mealworm larvae meal supplementation in broiler diets on meat quality

The aim of this study was to evaluate the effect of Tenebrio molitor larvae meal supplementation in chicken diets on the chemical composition and sensory quality of meat. The experiment was conducted on 120 Ross 308 male broilers from day 12 to day 38 of their age. Broilers were divided into three equal groups with 5 replicates per treatment. The two experimental groups received feed mixtures containing 2% (TM2; n = 40) and 5% (TM5; n = 40), respectively of yellow mealworm (Tenebrio molitor L.) meal. The third group (TM0; n = 40) was control, receiving 0% of mealworms in diet. The addition of mealworm meal to diets in this trial do not worsen the chemical composition or sensory characteristics of the thigh meat of broilers. The control chickens had a higher live weight (P < 0.05) compared to the experimental groups at the end of the trial. The lowest live weight and feed intake was determined in group TM2 (P < 0.05). The highest feed intake (P < 0.05) was found in the control group. The breast meat from the control group was rated better (P < 0.05) in flavour compared to the groups receiving 2% and 5% of yellow mealworms. The primary requirement for the use of any ingredient in feed is that it does not adversely affect food safety and quality. In our study, the inclusion of 2% and 5% mealworm meal in the broiler’s diet had no influence on meat quality.

Effect of Insect Live Larvae as Environmental Enrichment on Poultry Gut Health: Gut Mucin Composition, Microbiota and Local Immune Response Evaluation

The aim of this study was to evaluate the effect of Hermetia illucens (HI) and Tenebrio molitor (TM) live larvae as environmental enrichment on the mucin composition, local immune response and microbiota of broilers. A total of 180 four-day-old male broiler chickens (Ross 308) were randomly allotted to three dietary treatments (six replicates/treatment; ten animals/replicate): (i) control (C); (ii) C+HI; (iii) C+TM. Live larvae were distributed based on 5% of the expected daily feed intake. At slaughter (39 days of age), samples of duodenum, jejunum and ileum (twelve animals/diet) were submitted to mucin histochemical evaluation. Expression of MUC-2 and cytokines was evaluated by rt-qPCR in jejunum. Mucin staining intensity was not influenced by diet (p > 0.05); however, this varied depending on the intestinal segment (p < 0.001). No significant differences were recorded for IL-4, IL-6 TNF-α, MUC-2 and INF-γ gene expression in jejunum, while IL-2 was lower in the TM group compared to HI and C (p = 0.044). Caecal microbiota showed higher abundance of Clostridium, Saccharibacteria and Victivallaceae in the HI group, while Collinsella was higher in the TM group. The results suggested that live insect larvae did not impair mucin composition or local immune response, and can slightly improve caecal microbiota by enhancing a minor fraction of short chain fatty acid-producing taxa.

The Influence of Drying Methods on the Chemical Composition and Body Color of Yellow Mealworm (Tenebrio molitor L.)

To preserve the quality of the yellow mealworm, different drying methods are being explored by farmers and processors. However, the energy costs associated with these methods are usually high for smallholder insect-rearing farmers. Thus, the core aim of this study was to investigate different drying procedures and their impact on the chemical composition of yellow mealworm larvae. Yellow mealworms (exposed to sun, oven and freeze drying) were later analyzed for their chemical composition and body color. Crude protein (CP) content of freeze and oven-dried mealworms were similar (p > 0.05), but higher (p < 0.05) than those of the sun-dried samples. The b (yellowness) color of the sun-dried samples scored the lowest value (p < 0.05) in comparison with both oven and freeze-dried samples. The majority of the essential amino acids were higher (p < 0.05) in the sun-dried mealworms than both oven and freeze-dried samples. Similarly, the fat content of sun-dried mealworms was higher (p < 0.05) than if they had been oven or freeze dried. However, SFA (saturated fatty acids), PUFA (polyunsaturated fatty acids) and n-6 fatty acids were similar (p > 0.05) for all drying methods. We, therefore, conclude that sun drying resulted in the same nutritional composition as freeze and oven drying despite the noted color changes. Freeze and oven-drying strategies can be used to formulate mealworm-based feed and food products without noticeable nutritional changes. For the benefit of small-scale insect-rearing farmers, an appropriate drying technology that is affordable and easy to use should be developed considering the needs and experiences of these farmers.

Mealworm (Tenebrio molitor Larvae) as an Alternative Protein Source for Monogastric Animal: A Review

Simple Summary

Tenebrio molitor (T. molitor) larvae, known as mealworm, have been considered a good protein source for monogastric animals. They have a high quantity and quality of protein content and amino acid profile. The inclusion of T. molitor larvae in broiler diets improved the growth performance without having negative effects on carcass traits and blood profiles in broiler chickens, or had no influence on the growth performance and carcass yield of broiler chickens. The supplementation of T. molitor larvae improved the growth performance and protein utilization of weaning pigs. Furthermore, the replacement of fishmeal with T. molitor larvae resulted in no difference in the growth performance and nutrient digestibility of weaning pigs. However, there are some challenges regarding biosafety, consumer’s acceptance, and price for the use of T. moiltor larvae in animal feed. Consequently, T. molitor larvae could be used as an alternative or sustainable protein source in monogastric animal feed.

Abstract

Edible insects have been used as an alternative protein source for food and animal feed, and the market size for edible insects has increased. Tenebrio molitor larvae, also known as mealworm and yellow mealworm, are considered a good protein source with nutritional value, digestibility, flavor, and a functional ability. Additionally, they are easy to breed and feed for having a stable protein content, regardless of their diets. Therefore, T. molitor larvae have been produced industrially as feed for pets, zoo animals, and even for production animals. To maintain the nutrient composition and safety of T. molitor larvae, slaughtering (heating or freezing) and post-slaughtering (drying and grinding) procedures should be improved for animal feed. T. molitor larvae are also processed with defatting or hydrolysis before grinding. They have a high quality and quantity of protein and amino acid profile, so are considered a highly sustainable protein source for replacing soybean meal or fishmeal. T. molitor has a chitin in its cuticle, which is an indigestible fiber with positive effects on the immune system. In studies of poultry, the supplementation of T. molitor larvae improved the growth performance of broiler chickens, without having negative effects on carcass traits, whereas some studies have reported that there were no significant differences in the growth performance and carcass yield of broiler chickens. In studies of swine, the supplementation of T. molitor larvae improved the growth performance and protein utilization of weaning pigs. Furthermore, 10% of T. molitor larvae showed greater amino acid digestibility than conventional animal proteins in growing pigs. However, there are some challenges regarding the biosafety, consumer’s acceptance, and price for the use of T. moiltor larvae in animal feed. Consequently, T. molitor larvae could be used as an alternative or sustainable protein source in monogastric animal feed with a consideration of the nutritional values, biosafety, consumer’s acceptance, and market price of T. molitor larvae products.

Growth performance, serum biochemistry and meat quality traits of Jumbo quails fed with mopane worm (Imbrasia belina) meal-containing diets

Alternative protein sources such as mopane worm (Imbrasia belina) meal (MWM) are essential for sustainable poultry production. To date, no studies have attempted to investigate the effect of replacing soybean products with MWM in Jumbo quail diets. Thus, this study was designed to investigate the optimum inclusion level of MWM in place of soybean products on feed intake, physiological and meat quality responses of Jumbo quails. A total of 384 two-week-old mixed-gender quails (71.2 ± 5.40 g live-weight) were allotted to four isoproteic and isocaloric dietary treatments formulated by replacing soybean products with MWM at 0 (MWM0), 50 (MWM5), 100 (MWM10), and 150 (MWM15) g/kg. Neither linear nor quadratic effects (P > 0.05) were observed for feed intake, physiological responses, carcass traits and internal organs except for large intestines, which linearly decreased (P < 0.05) with MWM levels. There were significant quadratic trends for meat redness (a*), yellowness (b*) and chroma values in response to MWM levels. No dietary influences (P > 0.05) were observed on feed intake, physiological responses, internal organ weights, and carcass and meat quality parameters, except on b*, chroma and shear force. Diets MWM5 and MWM10 promoted higher (P < 0.05) b* and chroma values than MWM0. Whereas diet MWM5 promoted the highest (P < 0.05) shear force (2.39 N) than diets MWM0 and MWM10. We concluded that MWM has the potential to replace soybean products in quail diets without compromising their performance, health and meat quality. An optimum MWM inclusion level could not be determined suggesting that higher levels of MWM should be further investigated.

Yellow mealworm, Tenebrio molitor (Col: Tenebrionidae), larvae powder as dietary protein sources for broiler chickens: Effects on growth performance, carcass traits, selected intestinal microbiota and blood parameters

This study was conducted to evaluate the effects of dietary Tenebrio molitor larvae meal (TM meal) inclusion on the performance, carcass traits, caecum microbiota and blood parameters of broiler chickens. A total of 180-day-old chickens were allocated to three dietary groups with five replicate pens (12 birds/pen). Experimental diets were included a corn-soybean basal diet, and two diets with 2.5% and 5% TM. TM-included diets have been administered for periods of starter (1-10 days) and grower (11-25 days). A regular finisher diet was given to all groups during the 26-42 days of age. Diets containing TM meal did not influence feed intake and mortality percentage. Feed conversion ratio was lower with the 2.5% TM meal diet compared with the control group at starter period (p < .05). Besides, broiler chickens fed TM meal included diet had a higher body weight gain than the control group during 1-10 days of age (p < .05). The carcass characteristics and length and weight of different parts of small and large intestines were not influenced by diets. TM meal inclusion decreased the albumin-to-globulin ratio compared with the control group (p < .05). Additionally, lower total count of aerobic and Escherichia coli bacteria was observed in response to diet inclusion of 5% TM meal. Overall, the inclusion of TM meal in broilers' diet improved body weight gain and feed conversion ratio in the starting period, decreased albumin-to-globulin ratio and E. coli bacteria content.

Cafeteria-Type Feeding of Chickens Indicates a Preference for Insect (Tenebrio molitor) Larvae Meal

This study aimed to determine whether broiler chickens display a preference for Tenebrio molitor larvae (TM) meal by evaluating ingredient acceptability and birds' performance. Sixty 14-day-old male chickens were assigned into two treatment groups (5 birds/pen, n = 6) in a cafeteria-type study: the control (C) group, and the TM group. Each pen was equipped with one bell drinker and four through feeders allocated side by side; all feeders of the C group contained a complete standard diet whereas each feeder of the TM group contained one of the following ingredients: ground corn, extruded semi-whole soybean, vitamin-mineral supplement mixture, and TM meal. Feed intake was recorded daily and growth was monitored periodically up to day 32. Chickens which had access to individual feed components showed a delay to display preference for TM, but consumed, overall, up to 50% of the total intake as TM meal. Feed intake and growth performance were lower in all periods for TM group (p < 0.02), whereas feed conversion ratio was improved on days 22-28 and days 29-32 of age (p < 0.01). Data from bivariate and multidimensional analysis indicate that birds started to reach a balance of ingredient intake at 25 days of age, showing a high correlation between consumption of each ingredient and the day of the experiment. Chickens exhibited a preference for T. molitor meal, resulting in improved feed efficiency, which allows us to conclude that it can be a suitable feed alternative for poultry.