Degradabilidade in situ da matéria seca e proteína bruta de concentrados com diferentes fontes energéticas - DOI: 10.4025/actascianimsci.v26i2.1885

The degradation kinetics and the effective degradability (ED) of dry matter (DM) and crude protein (CP) of three concentrates, different in energetic sources composition, were assessed: STA = concentrate of high level of starch (56.6% of starch); OIL = concentrate of high level of oil (8.5% of oil) and S+O = concentrate composed of a mixture of STA and OIL (30.72% of starch and 6.05% of oil). The utilized starch and oil to compose the concentrate sources were corn and cottonseed, respectively. Three male bovines, averaging 352kg live weight and fitted with cannulae in the rumen, were used. For the 5%/h solid passage rate, it could be verified that the effective degradability (ED) of DM presented 69.17%, 61,15% and 52,99% for STA, S+O and OIL concentrates, respectively, which differed from each other (P<0.01). For the same passage rate, 5%/h, the ED of CP for the STA concentrate (79.42%) was different from S+O concentrate (69.41%), but both did not differ from OIL concentrate (73.59%). The S+O concentrate presented intermediate degradation offering more balanced ruminal fermentation conditions.