The effects of rumen protecting of soybean meal by fats and zeolite on ruminal degradability and intestinal digestibility of protein

This study evaluated the effects of coating of soybean meal (SMB) with the fat enriched in saturated fatty acid (SFA) and zeolite on rumen degradable dry matter (RDDM), rumen degradable protein (RDP) and intestinal digestibility of protein. Treatments were (1) SBM, (2) SBM protected with 40% SFA, (3) SBM protected with 38% SFA and 2% zeolite, (4) SBM protected with 50% SFA, (5) SBM protected with 48% SFA and 2% zeolite. To obtain the RDP fraction, samples were ruminally incubated for 16 h. The intestinal digestibility of crude protein was performed by three-step in vitro procedure. The results showed that SBM protecting with SFA reduced protein solubility compared with untreated SBM (P=0.002). The RDDM and RDP were decreased (P<0.05) with increasing fat level in the product. Using 2 % zeolite significantly decreased (P<0.05) RDP. There were no significant differences between SBM and SBM protected treatments in intestinal digestibility. It was concluded that protection of SBM with SFA decreased of RDDM and RDP, while RDP values showed more decrease with the inclusion of zeolite in the fat matrix.