Efeito da utilização de resíduos agroindustriais no desenvolvimento do trato intestinal de juvenis de tambaqui (Colossoma macropomum)

Abstract

Brazilian fish farming has vast production potential, driven by the distinct natural characteristics of the country, which have converged to provide this activity with satisfactory production rates in recent years. However, there are still some challenges to overcome, especially in nutrition. At the same time, tropical fruit production puts Brazil at the top of the production rankings, which generates a series of agro-industrial residues with great potential to create new high-quality by-products for use in animal nutrition. This research aimed to evaluate the use of agro-industrial waste in diets for juvenile tambaqui through morphological and histological analysis of the intestinal tract. Therefore, three experimental diets were prepared, one without the addition of fruit waste (control), one containing 30% acerola waste and another containing 30% guava waste, tested for 90 days on juvenile tambaqui in a 1000L water tank system. Body morphology parameters, digestive indices and intestinal and liver histology were analyzed. Of the results obtained for body morphology and digestive indices, only the length of the intestine showed a significant difference between the treatments, with the largest fish being those fed a diet containing acerola waste. With regard to the histological parameters of the intestine, the control diet showed better performance in terms of the height of the intestinal villi, enterocytes, supranuclear villi, and microvilli in the initial portion of the intestine. The treatments containing residues did not differ for these variables. It can, therefore, be concluded that although the fish fed the control diet had better intestinal histological characteristics, the fish fed the diets containing acerola and guava waste modulated their digestive tracts to make better use of the nutrients in the diets, obtaining the same productive gains as the fish fed a conventional diet.