Insects are a valuable source of nutrients for fish, but little is known about their nutritional value for Nile tilapia fingerlings. To evaluate the nutritional value and energy apparent digestibility coefficient (ADC) of five insects for Nile Tilapia male fingerlings, 900 fish were distributed in 18 fiberglass conic tanks, in a completely randomized design, with six dietary treatments (control, Nauphoeta cinerea meal (NCM) (Blattodea), Zophobas morio larvae meal (ZMM) (Coleptera), Gromphadorhina portentosa meal (GPM) (Blattodea), Gryllus assimilis meal (GAM) (Orthoptera) and Tenebrio molitor larvae meal (TMM) (Coleptera)) and three replicates (tanks), each containing 50 fish. The control diet had no insect meal included and the other five treatments comprised 80% commercial diet and 20% test ingredient with 0.1% chromic oxide as an inert marker. TMM presented a higher ADC for dry matter, protein, corrected protein and chitin than to other treatments (p < 0.01). GPM presented the highest ADC for lipids (p < 0.01). In general, the TMM presented better ADC of nutrients and energy and all the insect meals evaluated are potential feed for Nile tilapia fingerlings.

The present study aimed to evaluate the effect of dietary linoleic acid to linolenic acid (LNA/ALA) ratio on growth performance, feed utilization, plasma metabolite profiles, and muscle and liver fatty acid profiles of juvenile tambaqui Colossoma macropomum. Six diets were formulated to contain incremental levels of corn oil (rich in LNA) from 0 to 7% at the expense of linseed oil (rich in ALA), resulting in dietary LNA/ALA ratios ranging from 3.1 to 26.9. A control diet including fish oil was also formulated. The trial lasted 49 days, and each diet was assigned to six groups of fish with an initial body weight of 43 g. At the end of the trial, dietary LNA/ ALA ratio did not affect growth performance, feed utilization, and plasma metabolites profile, except for HDL that was lower in fish fed the 3.8 LNA/ALA diet than the 3.1 or 5.0 LNA/ALA diets. Whole-body protein content was lower in fish fed the control and 3.1 LNA/ALA diets. Composition of triglycerides, glucose and protein of liver and muscle was unaffected by dietary treatments. Eicosapentaeneoic acid (EPA, 20:5n-3) plus docosahexaenoic acid, (DHA, 22:6n-3) content of muscle decreased with the increase of LNA/ALA ratio. Fish fed 3.9-5.6 LNA/ALA diet showed the highest concentration of muscle ARA (arachidonic acid, 20:4n-6) and EPA + DHA among vegetable oil diets, though lower than that of fish fed the fish oil based diet. In conclusion, dietary LNA/ALA ratio should range between 3.9-5.6 to produce fillets with high EPA, DHA, and ARA contents, thus improving the nutritional quality of tambaqui fillets for human consumers.

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To evaluate the effects of the inclusion of three insect meals in dogs’ diets (Madagascar cockroach, MC; cinerea cockroach, CC; and superworm, SW) at two different levels (7.5 and 15%) on nutrients digestibility, blood parameters, faecal characteristics, volatile fatty acids, and gut microbiota, a digestibility trial was performed in a 3×2 factorial scheme in Latin square design 6×6. Experimental diets consisted of insect meals replacing the reference diet (dry and moist commercial feeds) on each of the two levels. Apparent metabolised energy of dry matter (AMEDM) was higher for dogs fed with SW than MC meal in both inclusion levels and, with CC meal at 7.5% of inclusion. The digestibility for dry and organic matter and protein was higher for dogs fed with SW than for MC meals. The faecal pH was lower for the dogs fed with CC than for the MC meal. Butyrate was higher for dogs fed with CC than MC and SW meals. Phenol was higher for dogs fed with MC than SW meal. The relative abundance of the phyla Proteobacteria and the genus Sutterella were higher at 7.5% of inclusion than 15%. Dogs fed with SW meal had a greater abundance of Prevotella, Faecalibacterium, and an unidentified genus in the family Ruminococcaceae than dogs fed with MC meal. The abundance of Allobaculum was higher for dogs fed with SW meal than CC meal. Even though all the insect meals evaluated can be included in adult dogs’ diets, the superworm meal appears as a highly digestible ingredient for dogs with lower negative impacts on intestine fermentative products and microbiota profile.