Effect of Dry Heat Temperature and Moist Heat Pressure on Canola Meal for Ruminant Utilisation. Part I: Nutritional, Protein Solubility and Degradability Characteristics

摘要

The effects of a range of barrel dry heat temperatures (20 to 180 oC), and moist heat pressure (MHP) (120 oC 15 min 192 kPa) on general nutritional, protein solubility, and in vitro protein degradability characteristics of canola meal were investigated. Increasing dry heat temperature was negatively correlated with meal crude protein (CP), soluble CP, neutral detergent fibre, acid detergent insoluble CP, and rapidly degradable (B1 Fraction) protein; and positively with NPN, intermediately degradable (B2 Fraction) protein, dry matter, lipid, carbohydrate, and in vitro rumen-undegradable protein. Relative to control meal, MHP increased in vitro rumen-undegradable protein, and in vitro CP digestibility; and decreased soluble protein, and 0.5% KOH solubility. Positive increases of Fraction A and B2, as B1 decreased, suggest barrel temperature induces protein hydrolysis and conversion of rapidly to intermediately degraded protein, respectively. The changes observed may have a great effect on ruminal degradation and supply of protein and AA for ruminant utilisation.