Nutritive values of corn, soybean meal, canola meal, and peas for broiler chickens as affected by a multicarbohydrase preparation of cell wall degrading enzymes

Abstract

The effect of a new multicarbohydrase supplement of cell wall degrading activities on the nutritive value of corn, soybean meal (SBM), canola meal (CM), and peas for broiler chickens was investigated. Four isoenergetic and isonitrogenous corn (69% corn), SBM (30% SBM, 59% corn), CM (30% CM, 54% corn), and pea (30% peas, 52% corn) diets, without or with enzyme supplementation, were formulated to meet NRC specifications for broiler chickens (except for AME and CP, which were at 95 and 92% of NRC requirements, respectively). The enzyme supplement supplied 1,000 U of xylanase, 400 U of glucanase, 1,000 U of pectinase, 120 U of cellulase, 280 U of mannanase, and 180 U of galactanase per kilogram of diet. Each diet was fed in a mash form to 9 replicate pens of 5 broilers from 5 to 18 d. When compared with the control treatment, enzyme addition to the corn diet improved (P < 0.05) feed-to-gain ratio, whereas the performance of birds fed the other 3 diets was not affected. An increase (P < 0.05) in total tract nonstarch polysaccharides (NSP) digestibility, ileal starch digestibility, and AMEn was observed in birds fed the enzyme-supplemented corn diet. An improvement (P < 0.05) in total tract NSP digestibility, ileal protein digestibility, and AMEn content with enzyme supplementation was observed for the SBM diet. However, nutrient digestibilities and AMEn of CM and pea diets were not affected (P > 0.05) by enzyme addition even though the NSP digestibilities increased significantly (P < 0.05). A significant increase (P < 0.05) in water-soluble NSP and a decrease (P < 0.05) in water-insoluble NSP concentration of ileal digesta was noted for birds fed all 4 enzyme-supplemented diets. It would appear from this study that the nutrient utilization of corn-SBM diet by broilers could be enhanced by using an appropriate multicarbohydrase enzyme supplement. The nutrient encapsulating effect of cell wall polysaccharides in SBM, CM, and peas may not be the only factor responsible for incomplete nutrient utilization. The improvement in feed efficiency and starch availability in birds fed corn diet likely resulted from the cell wall degrading activity of the enzyme supplement.