R. Bras. Zootec.01/Dec/2007;36(6):1742-50.
Chemical composition, characterization, and population of microorganisms on elephantgrass “Cameroon” (Pennisetum purpureum, Schum) and its silages
DOI: 10.1590/S1516-35982007000800006
Values of pH, ammonia nitrogen/total nitrogen (NH3-N), chemical composition, in vitro DM digestibility (IVDMD) and microbial populations of elephantgrass silages produced with enzymatic-bacterial inoculants, were evaluated in six fermentation periods (1, 3, 7, 14, 28, and 56 days), using laboratory silos. A 6 x 3 (six fermentation periods x three inoculants) factorial arrangement of treatments in a completely randomized design, with three replicates, was used. The following bacterial inoculants were evaluated: control (without inoculant), Sill All C4 (Alltech of Brazil) and Bacto Silo Tropical C (Katec). The CP, NDF and ADF contents were affected only by the fermentation period. The IVDMD, however, was affected by the inoculant × fermentation period interaction.The IVDMD concentration, however, was affected by the interaction between inoculant and fermentation period. There was a significant effect of inoculant and period on pH value, being observed reduction of 0.5769; 0.62327, and 0.80218 units/day of fermentation for the control silage, silage treated with Sil All, and Bacto Silo, respectively. It was observed inoculant × fermentation period interaction for NH3-N. The lactic acid bacteria population in the grass before ensiling was 104 cfu/gram of fresh forage, reaching maximum value of 108 cfu/gram of fresh silage at 14 days of fermentation to the control silage, and at 7 days of fermentation to the silages treated with inoculant. The enterobacter were not detected after the third day of fermentation and the maximum values of 104, <10, and 103 cfu/gram were registred for the silage to control, Sil All, and Bacto Silo Tropical C silages, respectively.
Keywords: ammonia nitrogen; enterobacter; lactic acid bacteria; molds; pH; yeasts