EVALUATION OF MOIST HEAT-TREATMENT OF CANOLA-MEAL ON DIGESTION IN THERUMEN, SMALL-INTESTINE, LARGE-INTESTINE AND TOTAL DIGESTIVE-TRACT OF STEERS

The effect of heat treatment on canola meal (CM) dry matter (DM) and n itrogen (N) degradability in the rumen and digestion in the small and large intestines and total digestive tract of steers was determined. C M was moist-heat-treated at 127 degrees C for 15 and 45 min. The degra dation of DM and N was estimated using small nylon bags in the rumen f or 0.1, 4, 8, 12, 16, 24, 48 and 72 h. The mobile bag technique with a n in vitro incubation in an acid-pepsin solution was used with a separ ate set of bags to estimate the digestion of each nutrient in the smal l and large intestines as well as the total digestive tract for rumen incubation times of 8, 16 and 24 h. Chemical analysis of heated CM sho wed a significant reduction in soluble N, sucrose and glucosinolate co ntent while the concentration of ADIN increased. Treatment significant ly reduced the degradation of DM and N in the rumen while the digestib ility of DM and N in the small intestine increased with both treatment s proportional to the decreased rumen degradation. Heat treatment had no effect on DM and N digestibility at the large intestine site. Total tract disappearance of DM and N were not affected by 15 min heating; however, after 45 min heating, DM and N disappearances were reduced. M oist heat treatment was effective in reducing rumen disappearance of C M nitrogen while it increased the N digestion in the small intestine.