Digestibilidade aparente de macrófitas aquáticas para o tambaqui Colossoma macropomum (Cuvier 1818)

Abstract

The biggest bottlenecks in aquaculture production is the provision of quality feed. Currently studies in the area of nutrition seek alternative foods. The objective of this study was to evaluate the digestibility of aquatic macrophytes (Eichhornia crassipes, Pistia stratiotes and Salvínia auriculata) to tambaqui (Colossoma macropomum). The randomized block design (DBC) with four treatments: T1 - diet reference; T2 - inclusion of 30% of Pistia stratiotes; T3 - inclusion of 30% of Salvinia auriculata; T4 - inclusion of 30% of Eichhornia Crassipes containing four replicates totaling 16 experimental units. The species used in the experiment was Colossoma macropomum (Tambaqui), with 112 animals (58 ± 7.07 g) being used, each experimental unit being composed of seven animals. The inert marker Chromium (Cr2O3) with 0.1% was used in the feeds. The Ghelph system was modified for a 30-day experiment. Statistical analyzes were performed using the Statistical Analysis Software (SAS) version 9.0 with a threshold of significance (P) of 0.05. Statistical differences were found for the Apparent Digestibility Coefficient (CDA) of crude protein (PB), ethereal extract (EE), crude fiber (FB) and energy (EN). The CDA values of these variables were significantly lower than those of the reference ration, indicating the lower efficiency of tambaqui to assimilate PB, EE, FB and EN contained in rations including Pistia stratiotes, Salvinia auriculata and Eichhornia Crassipes. Emergent aquatic macrophytes have a potential for use as an alternative food, apparent protein digestibility coefficients, ethereal extract, crude fiber and energy were better for Eichhornia crassipes. Indicating the use of up to 30% inclusion of Eichhornia crassipes for Colossoma macropomum.