Ruminal in situ degradability of dry matter and neutral detergent fiber of sugarcane silage

Abstract

The ruminal degradability of dry matter (DM) and neutral detergent fiber (NDF) of 9 sugarcane varieties ensiled 15 months after planting was evaluated, using 3 fistulated Holstein x Zebu cows and incubation periods of 0, 6, 12, 24, 72 and 96 h in a randomized complete block design. Dry matter, crude protein (CP), mineral matter (MM), NDF, pH and in-situ degradability levels were determined. There were significant differences in composition of all evaluated parameters in the silages, except for CP, with the following variations: DM (19.7–23.2%), CP (2.70–3.47%), MM (3.2–5.2%), NDF (67.6–73.8%) and pH (3.8–4.2). The DM fraction ‘a’ differed among sugarcane varieties, with SP 801816 presenting the highest soluble fraction (26.83%). Effective degradability (ED) of DM (32.7–40.9%) and degradation rate ‘c’ did not differ among varieties. The ED of NDF and fraction ‘a’ did not differ among silages, but there were significant differences in fraction ‘b’, with a variation from 36.4 to 41.2%. Highest NDF ED occurred for the varieties RB 835486 (22%) and SP 791011 (21.1%). Further studies with these two varieties with the addition of inoculants and additives at ensiling are needed along with feeding studies to determine animal performance data.