Determination of degradability of germinated and heated soybean seeds and its proteins fractions

Abstract

This study was carried out to determine the effects of germination and moisture heating treatments (121 °C with steam pressure) of soybean seeds (SS) on in situ rumen degradability characteristics in sheep and its proteins sub-units fractions by a SDS-PAGE discontinues system. In the experiments, three ruminally cannulated wethers were used to measure in situ rumen degradability characteristics of dry matter (DM) and crude protein (CP) of different treated SS samples. SS were treated germination and germination with moisture heating. Germination and moisture heated treatment significantly (P<0.05) reduced degradability values of DM and CP for SS. Rumen effective protein degradability values of SS (k=0.02 h^-1) were significantly decreased by germination with heating (P<0.05). Effective degradability of DM (k=0.02 h^-1) were 72.90, 68.36 and 67.83 percent of DM and CP was 71.53, 69.40 and 63.00 percent of DM for NSS (untreated soybean seeds), GSS (germinated soybean seeds) and HGSS (heated and Germinated soybean seeds) treatments, respectively. Electrophoretic patterns of untreated and treated SS protein residues revealed that β-conglycinin β, α and α` subunit were degraded completely within 24h of incubation in the rumen, whereas the acidic and basic subunits of glycinin were degraded after 48h incubation in GSS and HGSS. It is concluded that SS proteins can be effectively protected from degradation in the rumen by germination and germination with moisture heating treatment.