Effects of increasing inclusion of soybean molasses on rumen fermentation of feedlot sheep

The objective of this study was to evaluate increasing inclusions of soybean molasses on feed intake and rumen fermentation parameters of crossbred sheep. Nine cross-bred ruminally cannulated male sheep (71.1 ± 12.8 kg BW) were distributed in a triple Latin square 3 × 3 design. Treatments consisted of isonitrogenous (18.5% CP) and isoenergetic (2.7 Kcal ME/kg) diets, containing 0, 10 or 20% SM (DM basis). Before subsequent feeding, samples of orts were collected to monitor daily intake. After 14-d adaptation period rumen fluid samples were collected in each experimental period, at 0, 2, 4, 6, 8, 10, and 12 h after feeding, to measure pH, and evaluate NH3-N and VFA concentrations. The pH was measured immediately after rumen fluid sampling, and NH3-N concentrations was determined using a micro-Kjeldhal apparatus. The concentration of VFA was determined by gas chromatography. Data were evaluated with a Mixed procedure of SAS, with repeated measures over time. Orthogonal contrasts were used to determine the linear and quadratic effects of SM inclusions, as well as the contrast Control × SM treatments. There was no interaction of time of sampling × treatment for all variables evaluated (P > 0.05). The increasing inclusion of SM did not alter the feed intake and ruminal parameters of feedlot sheep (P > 0.05). In average, the DM, NDF and CP intakes were, respectively, 1.32, 0.434 and 0.235 kg/d. The average values of pH and concentrations of NH3-N, acetic, propionic, isobutyric, butyric, isovaleric and valeric acids were, respectively, 6.1, 13.0 mg/dL, 33.4 mM/L, 16.7 mM/L, 6.5 mM/L, 0.9 mM/L, 1.0 mM/L and 0.6 mM/L. The results indicate that the inclusion of soybean molasses at up to 20% (DM basis) in the diets for feedlot crossbred sheep does not affect the feed intake and ruminal parameters.