Silagem de cana-de-açúcar em duas idades de corte com diferentes aditivos

Abstract

The bromatological characteristics and in situ degradability of sugar cane (Sacharum spp.) with different additives at two cutting ages before and after ensiling process were evaluated. The treatments were arranged in a completely randomized design with three replicates. The additives utilized were 1% of urea, 8% of ground ears with husks, 0.5% of mineral and 1% of the urea + ammonium sulfate mixture, this latter, added only on the in natura cane. Sugar cane was cut at two cutting ages, chopped to particles of 0.2 to 0.5 cm, made additive and ensiled into PVC pipes 10 cm in diameter and 50 cm in length with a capacity for about 3 kg of silage. On the bottom of the silos, 1 kg of dry sand protected by a fine plastic screen and two layers of "serge" cloth were placed for determination of losses in the ensiling process. Further, the percentages and yields of dry matter (DM), contents of crude protein (CP), neutral and acid detergent fiber (NDF) and (ADF), pH and in situ degradability were determined. An increase of 25.19% in the dry matter yield of sugar cane from 11 to 24 months old of cutting took place. The values of pH did not range with cutting age, but they differed among the silages and in natura cane treatments. The in natura cane treatment added with 1% of the urea + ammonium sulfate treatment resulted into best bromatological and degradability values of dry matter relative to the other treatments. The ensiled material when made additive showed improvement in the contents of CP, NDF, ADF. The degradability of the dry matter of the silages was not affected by cutting age, it´s having significant differences only among the treatments utilized. In the ensiling process, variations in the losses by gases and recovery of dry matter only among cutting ages were found. But in the losses by effluent there was variation only among treatments.