Composição química e digestibilidade de fenos de três gramíneas amonizadas com ureia.

Abstract

The use of low quality roughage fodder treated by physical, chemical and biological means may be a viable alternative to supply good quality forage during the dry season. To evaluate the effect of urea ammoniation on the chemical composition and in vitro digestibility of dry matter (DIVMS) of Aristida setifolia, Eleusine indica and Rhynchelytrum repens hays, an experiment was carried out at UFCG / CSTR Patos- PB facilities according to a completely random design with 3x2 factorial treatments (hay of three grass species, treated or not treated with urea) and five treatment replications. Each treatment consisted of 7 kg of hay, and the concentration of NH3 was equivalent to 5% (weight) of the treated hay in a dry matter basis. Dry matter (DM), crude protein (CP), neutral (NDF) and acid (ADF) detergent fiber, mineral matter (MM) and lignin (LIG) contents, and “in vitro” digestibility of dry matter (DIVMS) from treated and untreated hays were compared. Treatment with urea affected (P <0.05) DM, CP, MM, NDFpc, NDFd, ADF, PBd, CHOTd contents of the hays of the three grass species. Urea treated hays showed an increased CP content, and the highest CP content was observed for Eleusine indica hay. Rhynchelytrum repens hay showed the highest FDA content, treated or not with urea, and the lowest value was for Eleusine indica hay. In vitro digestibility was affected independently, increasing (P<0.05) PDR and PNDRD contents. The PNDRD content was affected (P<0.05) by treatments and were dependent. Ammoniation with 5% urea improved the nutritional value of Rhynchelytrum repens, Aristida setifolia and Eleusine indica hays considering the increase in CP content and DIVMS.