The world population is increasing, and our current agricultural practices are not sustainable enough to address the concerns. Alternative proteins including plant-based proteins would provide a more sustainable source of food and feed ingredients. Among food systems, the aquaculture industry is rapidly growing, while still depending on marine sources as a main source of protein. Thus, using alternative plant-based proteins as a source for developing aquafeed would make this industry more viable. Sorghum is a valuable grain with high protein contents, proper mineral and fatty acids balance, and is available all around the world. However, sorghum has not been used widely for aquafeed development. In this review article, we cover sorghum production, composition, sorghum as a protein source for aquafeed development, and bioprocessing methods for enhancing the quality of sorghum.

A 12‐week growth trial was conducted to assess the effects of mealworm meals, as a substitution for fishmeal, on the growth, physiobiochemical responses, digesta microbiome, and immune‐related genes expression of Atlantic salmon (Salmo salar). Twenty Atlantic salmon parr (38.5 ± 0.1 g, initial weight) were stocked into each of 16 tanks in a recirculating aquaculture system. A fishmeal‐based diet (100% FM) was used as the control treatment and was compared with three test diets where: (1) fishmeal was partially (50%) replaced with defatted mealworm meal, Tenebrio molitor (50% DMM), (2) fishmeal was fully replaced with defatted mealworm meal (100% DMM), and (3) fishmeal was partially replaced with whole lesser mealworm meal, Alphitobius diaperinus (50% WMM). All substitutions were done on a crude protein basis. Each of the four experimental diets was evaluated in quadruplicate tanks as part of randomized design. The results indicated that Atlantic salmon showed high survival (greater or equal to 98.8%), and no significant difference in final growth, feed efficiency, feces stability and condition indices. Hepatosomatic index was lower in fish fed 100% DMM and 50% WMM when compared to fish fed the control diet (100% FM). Whole‐body proximate and amino acid compositions were not statistically different between treatments, while essential fatty acids, including linolenic, eicosapentaenoic acid, and homo‐a‐linolenic, were lower in fish fed 100% DMM. Plasma parameters (total protein, alanine aminotransferase, alkaline phosphatase, and total iron‐binding capacity), hepatic peroxide, and antioxidant enzymes were not significantly affected by dietary substitutions, whereas plasma immunoglobulin M showed significantly higher levels in fish fed 50% DMM and 100% DMM when compared to fish fed the control diet (100% FM). The inclusion of mealworm meals significantly impacted the overall microbiome composition but not the richness and evenness of the salmon digesta microbiomes compared to control. The most common genus in all treatments was Pseudomonas, which has been previously shown to have both commensal and pathogenic members. The relative expressions of growth (IGF‐I) and protein synthesis (TIPRL) were not significantly different between the treatments, whereas immunoglobulin genes (IgM, IgD, and IgT) were significantly upregulated in fish fed the DMM diets when compared to fish fed the control diet. Overall, this study suggests that the mealworm meals tested could be suitable alternatives to fishmeal in the diet of Atlantic salmon.

The digestibility of defatted mealworm (DMW, Tenebrio molitor ) and its substitution for fishmeal (FM) in rainbow trout ( Oncorhynchus mykiss ) diets was determined. In the first trial, a diet with 40% FM was considered as the control (Diet 1), and four other diets replaced 25% (Diet 2), 50% (Diet 3), 75% (Diet 4), and 100% (Diet 5) of FM with DMW. In the second trial, the in vivo digestibility of DMW was assessed. Results of the first trial showed no significant differences in fish growth and feed utilization performance among dietary groups ( p > 0.05). Fish fed the highest DMW level showed significantly higher whole‐body lipid and energy composition compared to fish fed the control diet. Substitution of FM with DMW did not significantly affect hematological electrolyte, acid–base, and blood gas parameters, except for sodium (Na) concentration. The measured mean score of histopathological features did not show significant degradation of the distal intestine when FM was completely replaced. A significantly lower liver inflammation was observed in fish‐fed Diet 3 compared to fish‐fed Diet 5. Based on the results of the second experiment, the apparent digestibility coefficient of dry matter, protein, lipid, energy, and phosphorus were 80%, 87%, 100%, 84%, and 90%, respectively, and all essential amino acid digestibility coefficients were >90%. Overall, the highly digestible DMW can fully replace FM in the diet, up to 40% as fed, with little to no impact on the health, growth performance, feed efficiency, and fillet composition. When considering all parameters evaluated, an inclusion level between 20% and 30% (as fed) or 50%–75% of FM replacement was found to yield the best performance and fish health.

Animal agriculture is under pressure to increase efficiency, sustainability, and innovation to meet the demands of a rising global population while decreasing adverse environmental effects. Feed cost and availability are 2 of the biggest hurdles to sustainable production. Current diets depend on sources of grain and animal byproduct protein for essential amino acids which have limited sustainability. Insects have arisen as an attractive, sustainable alternative protein source for animal diets due to their favorable nutrient composition, low space and water requirements, and natural role in animal diets. Additionally, insects are capable of bioremediating waste streams including agricultural and food waste, manure, and plastics helping to increase their sustainability. The insect rearing industry has grown rapidly in recent years and shows great economic potential. However, state-of-the-art research is urgently needed to overcome barriers to adoption in commercial animal diets such as regulatory restrictions, production scale issues, and food safety concerns. To address this need, the USDA Agricultural Research Service “MINIstoc: Model for INsect Inclusion” project was created to bring together diverse scientists from across the world to synergistically advance insect meal production and inclusion in animal diets. Here, we provide a short review of insects as feed while describing the MINIstock project which serves as the inspiration for the Journal of Economic Entomology Special Collection “Insects as feed: sustainable solutions for food waste and animal production practices.”

An in vivo trial was conducted to determine the apparent digestibility coefficients (ADCs) of insect meals for rainbow trout, Oncorhynchus mykiss. Rainbow trout (approximately 370 g ± 23 g, mean ± SD initial weight) were stocked 25 per tank into 400-liter tanks. Fish were fed a reference diet, or 1 of 5 test diets created by blending the reference diet in a 70:30 ratio (dry-weight basis) with menhaden fish meal (MFM), 2 house cricket (Acheta domesticus) meals (cricket A and cricket B), Galleria mellonella meal, and yellow mealworm (Tenebrio molitor) meal. Diets were assigned to 3 replicate tanks of fish and fed twice daily for 14 days prior to fecal collection. Ingredients, diets, and fecal matter were analyzed in duplicate for proximate, mineral, and amino acid composition. House cricket meals were 67.3% and 69.0% protein (CP) and 16.6% and 17.1% lipid (CL), for house cricket A and B, respectively. Yellow mealworm meal contained 56.5% CP and 27.7% CL, and G. mellonella larvae meal contained 32.5% CP and 54.2% CL. Protein ADCs were 78.9 for G. mellonella larvae meal, 78.0 for yellow mealworm meal, and 76.5 for house cricket A and not different from the MFM protein ADC of 76.6, while house cricket B protein ADC was 65.8 and was significantly lower than the MFM protein ADC (F = 7.39; df = 4,14; P = 0.0049). Together, these nutritional values suggest house crickets, and yellow mealworms show promise as alternative protein sources in salmonid feeds, with the potential of G. mellonella as an alternative lipid source.