Digestibilidade aparente da energia e nutrientes de tilápias (Oreochromis niloticus) alimentadas com rações contendo enzimas exógenas

Abstract

This study investigates the impact of using phytase and xylanase enzymes on the apparent digestibility in tilapias, aiming to develop less polluting feed and improve the utilization of plant-based ingredients. The objective was to assess the effectiveness of these enzymes in enhancing the coefficients of apparent digestibility of energy, nutrients, amino acids, and phosphorus, which are essential components in tilapia diets. The research was conducted using four diets: reference (T1), xylanase (T2), phytase (T3), and xylanase + phytase (T4). Juvenile Nile tilapia (n = 480, with an average weight of 57.67 ± 5.75g) were randomly distributed into four treatments, each with six replications. The results show that fish fed with diets T3 and T4, which included phytase, had higher phosphorus digestibility, corresponding to -11.54% and -13.35% respectively, compared to the reference diet. This indicates a reduction in the excretion of this mineral into the environment. The addition of exogenous enzymes did not significantly affect the digestibility of dry matter, gross energy, crude protein, and lipids. However, there was a decrease in arginine digestibility of -3.33% in the T4 group compared to the control, and a reduction of -1.75% in glutamic acid digestibility when compared to the diets of groups T2 and T4. The results suggest that the use of exogenous enzymes can improve phosphorus digestibility in diets with high fiber content, contributing to tilapia growth and efficiency while supporting a cleaner and more sustainable production system.