Suplementação de óleo essencial de orégano em dietas para pós-larvas de jundiá (Rhamdia sp): avaliação do desempenho zootécnico

Abstract

Aquaculture is the animal food production sector that grows faster in the world nowadays, which makes important the searching for developing the activity in a sustainable way. In this sense, the agroecological based aquaculture, with the rearing of native species and use of efficient organic feeding, emerges as a viable economic alternative for family farmers. Numerous recent studies have shown the potential to improve the growth performance of fish by dietary supplementation with alternative substances from natural products and, among these, the essential oregano oil has shown great results. Thus, the aim of the present study was to evaluate the effect of organic diet supplementation with oregano essential oil (0.0, 0.5, 1.0, 1.5 and 2.0 g/kg) on the performance of jundiá, Rhamdia sp. post-larvae. The experiment was carried out in a completely randomized design, with five treatments (dietary essential oregano oil concentrations) and four replicates. Groups of 60 jundiá post-larvae (15 days of age, 20 ± 5 mg of initial body weight) were stocked in 20 polyethylene tanks (65 L) connected to water recirculation system (~26 °C ), with individual aeration. The diets were prepared with certified organic ingredients and offered for 20 days in four daily meals. After the experimental period, fish survival and growth performance was verified. The post-larvae of jundiá fed actively and doubled in size, but there was no significant effect (P>0.05) of the different dietary essential oregano oil concentrations on survival and evaluated performance parameters (weight gain, specific growth rate, length gain, feed conversion ratio and fish condition factor). Given the importance of the topic, studies should be continued, evaluating the effects of dietary supplementation with this natural additive on growth and resistance to diseases of the jundiá in other stages of development and with longer periods of feeding.