The experiment was carried out at the Department of Animal Science of the Universidade Federal de Lavras and at the Food Laboratory at the Universidade José do Rosário Vellano (UNIFENAS), with the objective to evaluate the nutritive value of cotton textile mill waste using chemical composition (DM, CP, NDF, ADF) and ruminal degradability of the dry matter and NDF. The treatments were: T1 - in natura residue (IN); T2 - residue submitted to the pressure and steam treated (127ºC/1,5 kgf/cm²/35"; PS); T3 - 4% sodium hydroxide treated residue (four 24 hours; NaOH); T4 - 3% urea treated residue (for 28 days; U); T5 - 4% NaOH +3% urea treated residue (NaOH/U); T6 - pressure and steam + 4% NaOH treated residue (PS/NaOH); T7 - pressure and steam + 3% urea treated residue (PS/U). The results obtained in the chemical composition can allow concluding that combined treatments improved the nutritive value of the residue, as the NaOH/U treatment showed better results of CP, NDF, ADF. In the degradability experiment, it may be concluded that PS, U, NaOH/U, PS/NaOH and PS/U treatments were efficient in increasing effective degradability of DM, also resulted higher dry matter soluble fraction (a) and lower insoluble potentially degradable fraction (b). The treatments U, PS/NaOH and PS/U had higher values of effective degradability of NDF and higher soluble fraction (a). The combined treatments increased the degradability and nutritive value of cotton textile mill waste, and combined treatments with urea had the better results.
Degradability; sodium hydroxide; pressure and steam; urea; industrial by-products