The use of enzyme technology for improved energy utilization from full-fat oilseeds. Part I: canola seed.

The effect of carbohydrase enzyme supplementation on energy utilization from full-fat canola seed was investigated in a TMEn assay with adult roosters and in a nutrient digestibility and growth performance study with broiler chickens. In the TMEn assay, enzyme preparations C (cellulase, 340 U/g), XG (xylanase, 63,600 U/g and glucanase, 48,300 U/g), P (pectinase, 10,000 U/g), and MC (mannanase, 10,900 U/g and cellulase, 600 U/ g), alone and in combination (C + P, C + XG, C + MC, P + XG, P + MC, XG + MC, C + P + XG, C + P + MC, and C + P + XG + MC), were evaluated at an inclusion level of 0.1%. On average, hammer-milled canola seed with a TMEn content of 3,642 kcal/kg showed an increase (P < 0.05) to 4,783 kcal/kg following supplementation with the enzyme blends C + P + XG, C + P + MC, and C + P + XG + MC. A similar pattern of increase (P < 0.05) in fat (80.4 vs. 63.5%) and nonstarch polysaccharide (NSP; 20.4 vs. 4.4%) digestibilities was observed. Enzyme combination C + P + XG was further evaluated in a 2-wk (5- to 18-d) trial with broiler chickens fed isonitrogenous and isoenergetic corn and soybean meal-based diets containing canola seed (15%), the corresponding canola meal (8.85%) plus canola oil (6.15%) mixture, or canola seed (15%) supplemented with 3 different levels (0.002, 0.01, or 0.05%) of the enzyme. Poorer (P < 0.05) feed:gain (1.412 vs. 1.344), lower (P < 0.05) total tract DM (65.9 vs. 70.7%) and fat (69.6 vs. 88.0%) digestibilities, lower AMEn content (2,963 vs. 3,200 kcal/kg), and lower ileal fat (65.6 vs. 85.6%) and protein (75.6 vs. 81.2%) digestibilities were observed for the canola seed diet compared with the canola meal plus canola oil diet. Enzyme supplementation of the canola seed diet resulted in an improvement (P < 0.05) in feed:gain; total tract DM, fat, and NSP digestibilities; AMEn content; and ileal fat digestibility. Although the enzyme effect on ileal and total tract fat digestibilities was significant at both high and medium inclusion levels, other parameters showed the significant improvement only when the highest inclusion rate of enzyme was used. These data support the need for carbohydrase enzyme supplements in poultry diets containing full-fat canola seed.