Exúvia de Tenebrio molitor no desempenho produtivo de alevinos de tilápia vermelha

Abstract

One of the food strategies to promote the individual's resistance and stimulate growth is the addition of food additives. The objective of this study was to investigate the effects of the inclusion of different levels of Tenebrio molitor larvae exuvie (treated or not) on red tilapia fingerlings (Oreochromis sp.), taking into account the productive performance of the tested animals. Thus, the cultivation of the animals was done in the Pisciculture Sector of the Federal University of Lavras (UFLA), using 136 fingerlings, with initial weight and standard deviation of 4.13 ± 0.34 g, housed in 34 glass aquariums in closed water recirculation system. The experimental design was completely randomized, composed of five diets containing 0; 1.5; 3 and 4.5% inclusion of untreated exuvie and one containing 3% exuvie treated with 50% NaOH (chitin deacetylation, resulting in chitosan), and 7 experimental plots for each of the untreated and 6 treated treatments. After adaptation, the animals were fed three times a day for 36 days. At the end of the growing period, the fish were submitted to final biometry and biological material collection. The highest observed survival rate (91.67%) was that of the treatment with 3% of treated exuvie, and the other treatments did not reach 80% of survival each, under the same conditions of cultivation. In the performance parameters of the evaluated animals (final and daily average weight gain, average daily feed intake, apparent feed conversion, specific growth rate, mean difference in head height and total and standard body lengths, and hepatosomatic and viscerosomatic), there were no differences significant statistics between treatments (p > 0.05). It was concluded that the inclusion levels of T. molitor exuvie (chitin) in the diet of red tilapia fingerlings (Oreochromis sp.) did not improve the growth of the animals. However, treatment with the treated exuvie (chitosan) was promising to the other treatments in relation to the survival rate, giving indications of a beneficial action in the body of these animals.