Effects of a thermotolerant multi-enzyme product on nutrient and energy utilization of broilers fed mash or crumbled corn-soybean meal diets

An experiment was conducted to test the thermotolerance and efficacy of a new commercial multi-enzyme product containing amylase, protease, and xylanase activities in broilers fed diets in 2 physical forms (mashed and crumbled). The experiment consisted of 4 treatments for each form of diet: a control diet without enzyme (0 mg/kg) and test diets supplemented with 250, 350, or 450 mg/kg of a multi-enzyme product. Sixty-four male 36-d-old commercial Arbor Acres broilers were allocated into 64 wire cages that were then randomly divided into 8 treatments (8 replicate cages per treatment). Digestibility of diets and AME and TME values based on corn and soybean meal were measured by true methods. Endogenous losses were obtained from another 8 broilers. Excreta samples were collected to determine CP, gross energy (GE), and DM, and GE was analyzed for computation of AME and TME. Addition of the multienzyme product had a positive effect on nutrient utilization, including CP, DM, GE, AME, and TME, in broilers fed corn-soybean diets. Both mash and crumbled diets supplemented with 350 or 450 mg/kg of enzyme had significantly higher (P < 0.05) AME and TME values and apparent and true digestibility of DM, CP, and GE as compared with the lower enzyme diet or the control diet. Furthermore, increased levels of enzyme preparation caused a significant linear increase in the apparent and true digestibility of CP, DM, or GE and also linearly improved (P < 0.05) AME and TME for both the mash and crumbled diets. The crumbled diets had higher nutrient digestibility than the mash diets, regardless of whether enzyme was supplemented. In conclusion, addition of the multi-enzyme was effective in improving nutrient digestibility in 36-d-old broilers fed a corn-and soybean meal-based diet, and effects of the enzyme remained in the feed after pelleting. Therefore, the enzyme complex used in this study had the thermotolerance to withstand the heat treatment process of pelleting.