Effects of β-Mannanase (CTCzyme®) Supplementation on Growth Performance and Nutrient Digestibilities in Comparison to Multi-Enzyme Complexes in Broilers

As prices for feed ingredients rise, corn distillers dried grains with solubles (DDGS) have been used as a feed ingredient since DDGS production in the bioethanol industry has increased. However, DDGS contains a high percentage of non-starch polysaccharides (NSP) such as β-mannan, which is indigestible in non-ruminants. Therefore, supplementation of NSP-degrading enzymes in diets containing DDGS is widely accepted to increase nutrient utilization. A number of commercial products have been developed in the form of enzyme complexes due to concerns for various NSP in DDGS. The present study was conducted to evaluate the effects of β-mannanase (CTCzyme^®) supplementation on growth performance and nutrient digestibilities in broilers, and to compare its efficacy with other multi-enzyme complex products. A total of 36 twenty-day-old broiler chicks were housed in individual cages and fed one of the 4 experimental diets for 10 days. Basal diet was formulated to contain 10% DDGS and used for the control group (CON). Each of CTCzyme^® (800 U/g β-mannanase) and two enzyme complexes (product A: 7 U/g α-galactosidase, 22 U/g galactomannanase, 300 U/g xylanase, and 220 U/g β-glucanase; product B: 550 U/g xylanase and 50 U/g β-glucanase) were supplemented to the basal diet at 30% of recommended dosages (CTCzyme^®, 0.015%; A, 0.030%; B, 0.030%). Body weight and feed intake were measured on days 0, 6, and 10. For total tract digestibility, excreta from each bird were collected during days 6 through 10. Average daily gain (ADG) of CTCzyme^® treatment during day 6-10 was significantly higher (P<0.05) than CON. Body weights of A and B treatments at day 6 were lower (P<0.05) than CON, and BW of B treatment at day 10 was also lower (P<0.05) than CON. Although average daily feed intake (ADFI) was not different among treatments, a concomitant decrease in ADG and feed efficiency was noted in the group supplemented with B compared to other groups (P<0.05). There were no differences in nutrient digestibilities among treatments. Crude protein digestibility, however, tended to be higher in the group supplemented with CTCzyme^® than other groups. These results may implicate the comparable aspects of CTCzyme^® as a single NSP-degrading enzyme to multi-enzyme complexes A and B at 30% of recommended level in diets containing 10% DDGS.