Comparação de métodos in vitro para a quantificação da digestibilidade da matéria seca e da fibra em detergente neutro de forragens e concentrados

Abstract

The objective was to compare in vitro digestibility of dry matter (IVDMD) and neutral detergent fiber (IVNDFD) of forages and concentrates obtained using the incubators DaisyII and TE-150, and filter bags F57 (Ankon®) or non-woven textile (NWT - 100g/m2) in comparison with the values obtained using the Tilley and Terry (1963) method. Twenty-five samples of concentrates and 25 samples of forages were used. There were no differences between filter bags (P > 0.39) for IVDMD of forages. Higher IVDMD (P < 0.01) were observed for TE-150 compared to DaisyII. Estimates of IVDMD obtained with incubators and filter bags were higher (P < 0.01) than those obtained with the Tilley and Terry (1963) method. Higher IVNDFD (P < 0.01) were obtained with filter bags F57 regarding to NWT and TE-150 when compared to DaisyII. All values of the IVNDFD obtained with incubators and filter bags were higher (P < 0.01) than those obtained with the Tilley and Terry (1963) method. Both IVDMD and IVNDFD variables were greater using TE-150 incubator than using DaisyII (P < 0.04). Estimates obtained using NWT filter bags were higher (P < 0.01) than F57 filter bags. All methods were positively and strongly correlated (P < 0.01) to each other for IVDMD and IVNDFD. The repeatability and variances among samples for IVDMD and IVNDFD were similar among methods. In conclusion, all methods were similarly able to discriminate samples.