The Effect of Soybean Meal Heating Time on the in vitro Digestibility and Ruminal Fermentation Profile

The aim of this study was to determine the most optimal heating time in protection of protein rich feedstuff on digestibility and in vitro ruminal fermentation profile. Proteinous feedstuffs used in this study is soybean meal (Glycine max). This study is designed using one way ANOVA, with five treatments of heating time (T0 (control)= unheated, T1= 10 min, T2= 20 min, T3= 30 min, and T4= 40 min) at 120 ˚C and 6 replications. All the treatment samples then incubated for 48 h according to the 2-stage in vitro technique. The results showed that protecting soybean meal through heating decreased the dry matter (DM), organic matter (OM) digestibility, NH3 concentration and acetic acid:propionate ratio (A:P) (p < 0.05) compared with the control group. In general, there were no significant effects on ruminal pH, total and proportion of volatile fatty acids (VFA), and microbial protein. A decrease in NH3 concentration and A:P ratio was seen in T2 (49.05 mg/100 mL and 1.52, respectively). It can be concluded that protein protection in soybean meal through heat treatment can decrease rumen degradation. The best heating time for protecting soybean meal was found at 20 minutes.