Feasibility of wood pulping black liquor for treatment of soybean meal as a source of rumen protected protein

Abstract

This study was carried out to determine the effects of neutral black liquor and moisture heating treatments of soybean meal (SBM) on in situ rumen degradability characteristics in cow and its proteins sub-units fractions by sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) discontinuous system. SBM were treated with xylose, neutral black liquor and moisture heating. Neutral black liquor, xylose and moisture heated treatment significantly (P<0.05) reduced degradability values of crude protein (CP) for SBM. Treating could effectively decrease a fraction and increase b fraction in experimental treatments. Electrophoretic patterns of untreated and treated SBM protein shows that β- conglycinin α, ά and β subunit were degraded completely within 4 h of incubation in the rumen, whereas the acidic and basic subunits of glycinin were degraded after 48 h incubation in treated SBM with xylose and black liquor treated same as the xylose group. It is concluded that SBM proteins can be effectively and economically protected from degradation in the rumen.

Key words: Soybean meal; degradability; black liquor; moisture heat; SDS-PAGE.