Poultry Science Department, Texas A&M AgriLife Research.
Elanco Animal Health, Greenfield, IN.
Poult Sci. 2018 Feb 1;97(2):549-556. doi: 10.3382/ps/pex309.
An experiment was conducted to investigate the impact of β-mannanase inclusion on growth performance, viscosity, and energy utilization in broilers fed diets varying in galactomannan (GM) concentrations. Treatments were arranged as a 3 (GM concentration) × 3 (β-mannanase inclusion) factorial randomized complete block design with 12 replicates of 29 male broilers per replicate for a 42-d experiment. Efforts were made to reduce the amount of soybean meal, and thus GM, in the basal diet with guar gum included at 0, 0.21, or 0.42% to achieve a GM supplementation of 1,500 and 3,000 ppm, respectively. Beta-mannanase was included at 0, 200, or 400 g/ton. Broilers were fed a starter (d 0 to 14), grower (d 15 to 28), and finisher diets (d 29 to 42). Growth performance was monitored and ileal contents collected on d 14, 28, and 42 to determine ileal digestible energy (IDE) and intestinal viscosity. Increasing levels of GM negatively (P < 0.05) influenced body weight (BW) following the starter and grower periods and increased (P < 0.01) mortality corrected feed conversion ratio (FCR) throughout the study. Reduced growth performance was associated with increased (P < 0.05) intestinal viscosity and decreased (P < 0.05) IDE when GM inclusion was increased. Inclusion of β-mannanase in diets containing supplemental GM on d 28, increased average BW to levels similar to diets without supplemental GM. Improvements in FCR were also observed with β-mannanase inclusion in diets containing supplemental GM. Ileal digestible energy was increased (P < 0.05) with the addition of β-mannanase on d 28 of age. Multiple interactions in growth performance, intestinal viscosity, and IDE were associated with β-mannanase administration. In conclusion, β-mannanase improved IDE, reduced intestinal viscosity, and improved growth performance; however, the observed benefit was dependent upon dietary GM concentration.
进行了一项实验，以研究在不同半乳甘露聚糖（GM）浓度的日粮中添加 β-甘露聚糖酶对肉鸡生长性能、粘度和能量利用的影响。处理采用 3（GM 浓度）×3（β-甘露聚糖酶添加量）完全随机区组设计，每个重复 12 个 29 日龄雄性肉鸡，试验期为 42 天。研究人员努力减少基础日粮中豆粕的用量，并添加瓜尔胶，使其 GM 含量分别为 0、0.21 或 0.42%，从而分别补充 GM 1500 和 3000ppm。β-甘露聚糖酶的添加量为 0、200 或 400g/吨。肉鸡分别饲喂前期（0-14 日龄）、生长期（15-28 日龄）和后期（29-42 日龄）日粮。在第 14、28 和 42 天监测生长性能并收集回肠内容物，以测定回肠可消化能（IDE）和肠道粘度。随着 GM 水平的升高，生长期和生长期后肉鸡的体重（BW）呈负相关（P <0.05），试验期间死亡率校正的饲料转化率（FCR）也呈正相关（P <0.01）。随着 GM 添加量的增加，生长性能降低与肠道粘度增加（P <0.05）和 IDE 降低（P <0.05）有关。在含有 GM 补充剂的日粮中添加β-甘露聚糖酶可提高 BW，使其达到不含 GM 补充剂日粮的水平。在含有 GM 补充剂的日粮中添加β-甘露聚糖酶还可提高 FCR。在第 28 天添加β-甘露聚糖酶可提高 IDE（P <0.05）。在生长性能、肠道粘度和 IDE 方面存在多种相互作用与β-甘露聚糖酶的添加有关。综上所述，β-甘露聚糖酶提高了 IDE，降低了肠道粘度，改善了生长性能；但观察到的益处取决于日粮 GM 浓度。
