PSXIII-39 Feed intake and in vitro digestibility of sheep fed high concentrations of soybean molasses

Abstract The objective with this study was to evaluate the effects of high concentrations of soybean molasses (SM) on dry matter and nutrient intake and in vitro dry matter and nutrients digestibility. Nine ruminally-cannulated male crossbred sheep were assigned to a triple 3 × 3 Latin square design. Treatments consisted of diets containing 0 (M0), 15 (M15) or 30% (M30) SM (DM basis), replacing corn. Diets were composed of corn silage (40%) and concentrate (corn cracked grain [except for M30], wheat bran, soybean meal, urea, mineral-vitamin mix, and soybean molasses [except for M0]). Each experimental period lasted 21 d (14-d adaptation and 7-d data collection). Animals were fed twice daily (0800 and 1600 h) and feed delivered and refused were weighed every morning to calculate the intake of DM, NDF and CP. For in vitro digestibility evaluation, the Ankom Daisy II incubator was used. At d 20 of each experimental period, ruminal content was manually collected and strained with cheesecloth. Rumen fluid (400 mL) was placed into each fermentation jar, with 1330 mL buffer A and 266 mL buffer B. The jars were purged with CO2, and incubated at 39oC for 72 h. When the incubation completed 48 h, 8 g pepsin and 40 mL HCl 6N were added. Data were analysed using the MIXED procedure of SAS. Contrasts were used to determine the linear and quadratic effects, as well as Control × SM treatments. The SM addition quadratically affected IVDMD (P = 0.005) and IVNDFD (P = 0.002), with greater values observed for M15 (87.9 and 63.6%, respectively), while no effect was observed on IVCPD, DMI, NDFI and CPI. The results show the inclusion of up to 30% SM in crossbred feedlot sheep diets does not affect DM and nutrients intake, nor IVCPD, while 15% SM improves IVDMD and IVNDFD.