The influence of heat and chemical treatment on ruminal disappearance of canola meal

Abstract

The influence of temperature (125 or 145 °C) and duration (10, 20 or 30 min) of heating, or chemical treatment (acetic (AA) or formic (FA) acid) on in vitro insoluble DM (IDM) and insoluble CP (ICP) and 12 h in situ ruminal disappearance of canola meal was examined. Ruminal disappearances of dry matter (DDM) and crude protein (CPD) were expressed as apparent (ADMD and ACPD), insoluble (IDMD and ICPD) and degradable (DDMD and DCPD). Insoluble DM content was reduced by AA and FA (P < 0.01), while ICP was reduced by FA (P < 0.01). Acid treatment had no effect on in situ DMD or CPD. Heating increased IDM and ICP (P < 0.01). Duration of heating increased ICP at 145 °C (P < 0.01). Apparent DMD was influenced by temperature (P < 0.01) but not duration of heating. Mean ADMD and ACPD for control, 125 and 145 °C were 57.8, 59.6; 36.8, 24.1; and 27.4%, 13.7%, respectively, (P < 0.01). Insoluble and degradable DMD and CPD were reduced by heating (P < 0.01) but the influence of temperature or duration of heating was not consistent. The results indicate that heating at 125 or 145 °C for 10 min or more will reduce in situ DM and CP disappearance of canola meal, and increase the post-ruminal supply of DM and CP. Key words: Canola meal, in vitro solubility, in situ digestibility, heat and acid treatment