Programação nutricional com farinha de tenébrio gigante (Zophobas morio) na alimentação de alevinos de tilápia do Nilo

Abstract

Insect meal is a promising source, rich in protein, lipids and other nutrients and can be used as a substitute for animal or vegetable protein. However, the lack of chitinolytic enzymes in the gastrointestinal tract of some fish, necessary for chitin breakdown, causes the non-utilization of this raw material. Confronting this, the application of nutritional or metabolic programming is interesting, since exposure during the animal’s development phase to a stimulus of endogenous or exogenous origin can lead to long-term structural or functional changes. Therefore, based on the nutritional programming concept in mammals, this project evaluated the ability of tilapia fingerlings to use diets with a high content of insect meal on the lipid profile and intestine oxidative stress after consuming giant mealworm (TG) during larviculture. To carry out the test, initial preparation in the larval stage with the presence or not of SW meal was necessary. After 40 days, biometry was performed, with male fingerlings (3.1 ± 0.08 g average weight) reallocated in groups in a 2x3 factorial design with or without TG and experimental diets (0, 150 and 300 g/Kg TG) fed twice a day for 60 days. After those 60 days, they were euthanized and fillet and liver were collected for fatty acid analysis (FA); plasma for triglycerides, protein, NAG, cholesterol and total protein analysis and finally, the midgut for oxidative stress. Regarding FA in fillet and liver, it was observed that the diet with the TG inclusion increased SAFA and MUFA, this not being true for PUFA. In the liver, similar to PUFA, HUFA decreased with the TG inclusion. Only in the liver it was possible to visualize the effect of nutritional programming, this being reflected in the parameters C16:0, C20:4n6, C22:6n3, n3, HUFA, SAFA, n3/n6 ratio a decrease and an increase over C20:3n3 and n6/n3 ratio, however the observations are restricted to the 0 diet. The FA profile found in both tissues reflected negatively on the nutritional quality index, with the TG inclusion. In plasma, only NAG, protein and triglycerides were significant for programming. NAG and protein content were higher in the fish submitted to programming, while the triglycerides of the 0 and 150 g/Kg diets were lower, not being true for the 300 g/Kg diet. Catalase, superoxide dismutase and TBARS were evaluated on oxidative stress, however they did not show significant effects. The histopathology and lipid inclusion in the liver were not significant, except for vacuolization, that was lower in the 300 g/Kg TG inclusion diet. In conclusion, nutritional programming and diets were able to interfere with the lipid profile and liver vacuolization and plasma parameters. The results for the lipid profile found that the diets were not able to interfere with the animal’s health since the 300 g/Kg TG inclusion led to a decrease in vacuolization in the liver. We also highlighted the nutritional programming influence for the chitin use, demonstrating the possibility of including insect meal in fish feed.