Effect of a multiactivity non-starch polysaccharide degrading enzyme on broiler growth performance and nitrogen utilization: a meta-analysis of own trial data

Adding fiber-rich materials to poultry feed can reduce feed cost, but it increases the content of both soluble and insoluble non-starch polysaccharides (NSPs) which decreases nutrient availability. A multiactivity enzyme, AveMix® XG 10 containing glucanase and xylanase, has been developed to ensure the breakdown of the total NSP of fiber-rich feed. A meta-analysis was performed to quantify the effects of this enzyme on the growth performance and nitrogen (N) utilization of broilers, and identify potential modulating factors. The database was made up of 18 trials for a total of 110 dietary treatments conducted between 2003 and 2021. Broilers were fed either based on wheat or corn, and these received a different coding for statistical analysis. The experimental groups were control diets without enzyme or diets with supplementation of the enzyme (ranging from 25 ppm to 100 ppm). Two sub-databases were created to study the impact of growth phase, one for starter (first phase beginning before 7 days of age; 45 dietary treatments) and another for grower/finisher (ending before or at 42 days of age; 65 dietary treatments). Performance criteria were average daily gain (ADG), average daily feed intake (ADFI) and feed conversion ratio (FCR). During the starter phase, enzyme supplementation at 100 ppm linearly increased ADG (0.81 g/d; P < 0.001) and had no impact on ADFI and FCR. During the grower/finisher phase, 100 ppm supplementation increased the ADG of broilers fed with wheat by 6.89 g/d and by 0.58 g/d for the broilers fed with a corn-based diet (Enzyme, P < 0.001; Enzyme × Diet type, P < 0.001). FCR was beneficially reduced by 0.165 for the broilers fed with wheat, and by 0.0471 for the broilers fed with corn (Enzyme, P < 0.001; Interaction Enzyme × Diet type, P = 0.049). ADFI was unaffected by enzyme supplementation. Analysis of N balance during the increased N retained with enzyme in the starter (P = 0.039). During the grower/finisher phase, the enzyme increased N retained (P < 0.001) and N efficiency (P < 0.001), and decreased N excreted (P < 0.001). An interaction between enzyme supplementation and diet type for N retained (P = 0.002) and N efficiency (P = 0.010) occurred due to a higher impact on wheat-based diets. This study shows that the use of AveMix® XG 10 improves the broiler growth performance and N efficiency. These improvements are found to be greater with wheat- vs corn-based diets in the grower/finisher phase.