The use of enzyme technology for improved energy utilization from full-fat oilseeds. Part II: Flaxseed

An in vitro incubation study was carried out to determine whether various carbohydrase preparations contained appropriate activities to target nonstarch polysaccharides (NSP) of full-fat flaxseed. 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, P + XG, C + P + XG, C + P + MC, and C + P + XG + MC), were evaluated. Triplicate samples of defatted flaxseed meal (0.1 g) were incubated with 1% single enzymes or combinations at 45 C and pH 5.2. A more pronounced degradation of NSP was achieved when the enzyme preparations were used in concert. Compared with the control (no enzyme) treatment, the degree of NSP degradation averaged 34.7% when the sample was incubated with the 3 most effective enzyme combinations (C + P + XG, C + P + MC, and C + P + XG + MC). The effect of carbohydrase enzyme supplementation on energy utilization from full-fat flaxseed was investigated in a TMEn assay with adult roosters. When compared with the nonsupplemented sample, an increase (P < 0.05) in TMEn content from 2,717 to 3,751 kcal/kg (on average) was observed for the flaxseed supplemented with enzymes C + P + XG, C + P + MC, and C + P + XG + MC. A similar pattern of increase (P < 0.05) in fat and NSP digestibilities was noted. Enzyme combination C + P + XG was further evaluated in a 2-wk (5- to 18-d) trial with broiler chickens fed a corn and soybean meal-based flaxseed (15%) diet or the flaxseed diet supplemented with the enzyme at 3 different levels: 0.002, 0.01, and 0.05%. When supplemented at the highest level, the enzyme blend improved (P < 0.05) feed: gain, total tract DM, fat and NSP digestibilities, AME(n) content, and ileal fat digestibility. No effect of enzyme supplementation, regardless of the level used, on ileal protein digestibility and digesta viscosity was observed. The results of the current study suggest that multiactivity carbohydrase enzyme supplements may be used as a means to improve energy utilization from full-fat flaxseed and, thus, enhance its feeding value for poultry.