EVALUATION OF HYBRID SORGHUM FOR SILAGE THROUGH IN SITU DEGRADABILITY

The experiment was carried out in order to evaluate in situ degradability and the degradation kineticsof dry matter, crude protein, neutral detergent fiber and acid detergent fiber of silages of three sorghum genotypes. Twoisogenic lines of grain sorghum (CMSXS 114 and CMSXS 165) and one sorghum hybrid (double purpose, BR-700)were used. The plantation of the genotypes was carried out in summer/2009, in seedbeds 5 m long, 3 m wide and 0.75m row spacing. After cutting, the material was ensilaged. After the opening of the silos the samples were pre-dried,milled and stored in glass bottles for analyses of dry matter, crude protein, neutral detergent fiber, acid detergent fiber,hemicelluloses, cellulose and lignin, pH, NH3/NT and in situ digestibility of the dry matter. An entirely randomizedexperimental design was used, with four replications and four treatments, and the means were compared by the Tukeytest at 5% significance. As for degradation rate of DM, the ensilage of CMSXS165 line without tannin was superior toall of the treatments. The isogenic line genotype without tannin (CMSXS 165) presented greater effective degradabilityof CP than the line with tannin (CMSXS 114). Thus, the results found in this experiment allow concluding that thepresence of tannin can reduce the rumen degradability of the dry matter and crude protein of the ensilages.