It was evaluated the addition of calcium oxide (0; 0.5; 1.0; 1.5; and 2.0% of dry matter) effect on the chemical composition and ruminal degradability of the dry matter and neutral detergent fiber, on the losses of dry matter, and on the microbial population in sugar cane silages. A design with five levels of calcium oxide and three replications was used. All the variables were influenced by the addition of calcium oxide in the silages, except the composition in acid detergent insoluble protein, water soluble carbohydrates and lignin. The dry matter content and pH linearly increased while the contents of organic matter, hemicellulose and crude protein linearly decreased with the levels of calcium oxide. Neutral detergent fiber corrected for ashes and protein and acid detergent fiber were adjusted for the quadratic models with calculated minimal values of 33.3 and 22.5% for the levels 1.73 and 1.49% of calcium oxide, respectively. The in vitro digestibility of the dry matter and the content of amoniacal nitrogen adjusted to quadratic models with maximal levels of 80.1% and 9.1% for the levels of 1.8 and 0.7% of calcium oxide, respectively. The minimal production of gas (3.18%) was observed at the level of 1.39% of calcium oxide. Production of effluent and recovery of dry matter of the ensiled mass showed a reduction and a linear increase, respectively, with addition of calcium oxide. The highest lactic acid bacterial population was observed in the silage treated with 1.5% of calcium oxide. The addition of calcium oxide increased degradability of the soluble fraction of the dry matter, which was higher than 50% and reduced the non- degradable fraction of the neutral detergent fiber. Addition of calcium oxide level higher than 1.0% in the sugar cane during ensilage improves in vitro dry matter digestibility and the recovery of dry matter, increases populations of lactic acid bacteria and reduces production of yeasts.
effluent; ensilage; microbial population; nutritional value; whitewash
