This study evaluated the effects of supplemental xylanase and xylooligosaccharides (XOS) in a corn-soybean meal (SBM)-based diet on growth performance and intestinal health of broilers. A total of 288 day-old chicks (Cobb 500) were allocated to 36 floor pens (8 birds/pen) equally in 9 dietary treatments in a 3 × 3 factorial arrangement. The treatments were combinations of 3 levels of xylanase (0, 0.005% and 0.01% Econase XT) and 3 levels of prebiotics (0, 0.005% and 0.01% XOS) added to basal mash diets formulated in three phases (starter, d 0–14; grower, d 15–28; finisher, d 29–42). The feed intake and body weights were recorded weekly. On d 42, ileal sections were collected for histomorphometric and gene expression analysis, and cecal content was collected for determining short-chain fatty acids (SCFA) and microbiota. Xylanase linearly (P < 0.01) increased the average daily gain (ADG) in both the finisher and total period and the final body weight gain (FBWG, 2940 & 2932 vs. 2760 g) of broilers. XOS did not significantly increase either ADG or FBWG (P > 0.05). Supplemental xylanase and XOS did not affect average daily feed intake and feed conversion ratio (P > 0.05). Xylanase and XOS did not change villus height (VH) or crypt depth (CD) ratio (P > 0.05). However, xylanase exhibited a trend (P = 0.097) on VH:CD ratio. The inclusion of 0.01% XOS without xylanase increased the level of IL-10 (a marker of anti-inflammatory cytokine) and IL-4 (a T-cell differentiation cytokine) genes compared with control (P < 0.05). The acetate production was increased by xylanase (P < 0.01) and XOS (P < 0.05) without an additive effect. Xylanase increased total SCFA (P < 0.01) while XOS had a tendency to increase (P = 0.052). Alpha and beta diversity of microbiota among treatments were not different (P > 0.05). However, the mean proportion of family Ruminococcaceae was increased by the supplemental 0.01% xylanase (P < 0.01). It can be concluded that XOS can enhance cecal fermentation, while xylanase can increase the body weight gain along with the fermentation metabolites in the ceca of broilers fed the corn-SBM-based diet but the effects may not always translate into an improved mucosal absorptive capacity and a better feed efficiency.

中文翻译：

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补充木聚糖酶和低聚木糖对肉鸡生产性能和肠道健康变量的影响

本研究评估了在基于玉米豆粕 (SBM) 的日粮中添加木聚糖酶和低聚木糖 (XOS) 对肉鸡生长性能和肠道健康的影响。总共 288 只日龄雏鸡（Cobb 500）按 3 × 3 的因子安排在 9 种日粮处理中平均分配到 36 个地板围栏（8 只鸡/围栏）。处理是将 3 种水平的木聚糖酶（0、0.005% 和 0.01% Econase XT）和 3 种水平的益生元（0、0.005% 和 0.01% XOS）添加到基础饲料中，分三个阶段（起始，d 0- 14；种植者，第 15-28 天；育肥者，第 29-42 天）。每周记录采食量和体重。在第 42 天，收集回肠切片用于组织形态计量学和基因表达分析，并收集盲肠内容物以确定短链脂肪酸 (SCFA) 和微生物群。木聚糖酶线性（P < 0。01) 增加了肉鸡在育肥期和整个时期的平均日增重 (ADG) 以及最终增重 (FBWG, 2940 & 2932 vs. 2760 g)。XOS 没有显着增加 ADG 或 FBWG（P > 0.05）。补充木聚糖酶和 XOS 不影响平均日采食量和饲料转化率（P > 0.05）。木聚糖酶和 XOS 没有改变绒毛高度 (VH) 或隐窝深度 (CD) 比 (P > 0.05)。然而，木聚糖酶在 VH:CD 比率上表现出趋势 (P = 0.097)。与对照相比，包含 0.01% 不含木聚糖酶的 XOS 增加了 IL-10（抗炎细胞因子的标志物）和 IL-4（一种 T 细胞分化细胞因子）基因的水平（P < 0.05）。木聚糖酶 (P < 0.01) 和 XOS (P < 0.05) 增加了醋酸盐产量，但没有加成效应。木聚糖酶增加了总 SCFA（P < 0. 01) 而 XOS 有增加的趋势 (P = 0.052)。处理间微生物群的α和β多样性没有差异（P > 0.05）。然而，添加 0.01% 木聚糖酶增加了瘤胃球菌科的平均比例（P < 0.01）。可以得出结论，XOS 可以增强盲肠发酵，而木聚糖酶可以增加肉鸡在盲肠中的体重增加和发酵代谢物，但这种作用可能并不总是转化为改善的粘膜吸收能力和更好的饲料效率。