Farinha de inseto como fonte protéica em dietas para juvenis de tilápia (Oreochromis niloticus)

Abstract

Aquaculture in Brazil has developed in recent years, but the scarcity and high cost of fishmeal used in feed formulation highlights the need for sustainable alternatives, such as the use of insects as a source of protein. The application of these alternatives can optimize production and increase the efficiency and profitability of the sector. The aim of this study was to evaluate the effect of different levels of substitution of fishmeal protein by insect meal protein on the feeding preference of nilotic tilapia (Oreochromis niloticus). The work was subdivided into two independent experiments, both with the same experimental design. In each experiment, 60 juvenile tilapia were used (average weight 67.3 ± 12.39 g), housed in 60 aquariums (40 L), kept in a recirculating water system. In each trial, the animals were given four diets containing 0, 33, 66 and 100% substitution of fishmeal protein with black soldier fly larvae meal in the first experiment and housefly larvae meal in the second experiment. In the first experiment, the fish showed no clear preference between diets with and without black soldier fly, when the substitution was 33% of the feed. However, in contrasts with substitutions of 66% and 100%, there was greater acceptance of the diets with less substitution. The fish's daily consumption of the feed reflected their food preference, showing that there was no significant difference between the diets with 0% and 33% substitution of fishmeal protein by black soldier fly meal protein. In the second experiment, the fish preferred diets with a higher inclusion of black soldier fly meal compared to diets without this ingredient. However, there was no clear preference between different levels of substitution (33%, 66% and 100%). The highest consumption was recorded for animals fed diets containing 66% substitution, while for comparisons between 33% and 100%, the 33% diet was the most consumed by the fish Diets without houseflies resulted in lower consumption in percentage per gram of live weight of the fish. We conclude that replacing fish meal protein with black soldier fly meal protein in diets for juvenile Nile tilapia is recommended up to 33%, due to the possible presence of factors that may compromise fish intake and growth. On the other hand, housefly meal is well accepted by animals up to 66% replacement.