Age and dietary xylanase supplementation affects ileal sugar residues and short chain fatty acid concentration in the ileum and caecum of broiler chickens
Age and dietary xylanase supplementation affects ileal sugar residues and short chain fatty acid concentration in the ileum and caecum of broiler chickens
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DOI：
10.1016/j.anifeedsci.2017.07.017
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发表时间：
2017-12-01
影响因子：
3.2
通讯作者：
Bedford, M. R.
中科院分区：
文献类型：
--
作者：
Lee, S. A.;Apajalahti, J.;Bedford, M. R.
本研究旨在探讨木聚糖酶诱导肠道中可溶性糖、短链脂肪酸(SCFA)和微生物含量变化与肉鸡生产性能的关系。对328只罗斯508公鸡进行了为期42天的试验，分为两个处理组，分别饲喂含或不含木聚糖酶(0或16000BXU/kg)的小麦日粮。每组有8个重复栏(每栏13只鸡)，每个处理增加3个重复取样栏(每栏20只鸡)。早期体重差异显著，饲喂木聚糖酶的雏鸡在第11天和第21天分别比对照组重21g(P=0.02)和39g(P=0.10)。在整个42天的试验期内，添加木聚糖酶的日增重(BWG)和饲料转化率(FCR)与对照组没有显著差异，这可能是由于两种处理的雏鸡都表现出了较高的生产性能。添加木聚糖酶提高了回肠中可溶性阿拉伯糖和木糖残留量(P<；0.05)，降低了各日龄雏鸡回肠粘度，提示阿拉伯木聚糖降解为可溶性低聚糖。木聚糖酶对盲肠中可溶性糖残留量无显著影响。无论处理如何，11日龄雏鸟盲肠中的可溶性糖残留量都相当高，这可能说明雏鸟的营养物质消化和吸收能力较差。在第21天，木糖和阿拉伯糖在盲肠总可溶性糖中的比例下降(P<；0.001)，这表明驻留细菌对木糖和阿拉伯糖的利用更多。42日龄时，饲喂木聚糖酶的雏鸡双歧杆菌数量显著高于对照组(P=0.01)。水平(5.7e(+10)vs.8.1e(+9))可增加盲肠中醋酸(P=0.002)和丁酸(P<；0.001)的含量，降低乳酸水平(P=0.03)。在所有年龄段，木聚糖酶处理降低了支链挥发性脂肪酸在总SCFA中的比例(P=0.04)，表明蛋白质发酵减少。这些发现表明，小麦阿拉伯木聚糖酶对小麦阿拉伯木聚糖的较大降解可以促进特定细菌在盲肠中的定植和SCFAs的产生，这一事件可能与改善肉鸡的生产性能有关。
The objective of this study was to investigate how xylanase-induced changes in soluble sugar, short chain fatty acid (SCFA) and microbial content of the gut might be linked to broiler performance. A 42-day experiment was conducted using 328 male Ross 508 broiler chicks divided into two treatment groups, fed wheat-based diets with or without xylanase (0 or 16,000 BXU/kg). Each group had 8 replicate pens (13 birds per pen), with 3 additional replicate sampling pens per treatment (20 chicks per pen). Early body weight differences were shown, with xylanase-fed birds being 21 g (P = 0.02) and 39 g (P = 0.10) heavier at days 11 and 21 than control birds. Over the entire 42 day experimental period, body weight gain (BWG) and feed conversion ratio (FCR) with xylanase supplementation were not significantly different from the control, possibly due to the high performance of birds in both treatments. Xylanase supplementation increased (P < 0.05) soluble arabinose and xylose residues in the ileum and decreased ileal viscosity of birds at all ages, suggesting arabinoxylan degradation to soluble oligosaccharides. Xylanase had no significant effect on soluble sugar residue concentration in the caecum at any age. Irrespective of treatment, caecal soluble sugar residue content was considerably higher in 11 day-old birds, possibly illustrating poorer nutrient digestion and absorptive capacity of young birds. The proportion of xylose and arabinose residues in total caecal soluble sugars decreased (P < 0.001) at day 21, suggesting greater utilisation by resident bacteria. At day 42, compared to the controls, xylanase-fed birds had higher (P = 0.01) Bifidobacterium spp. levels (5.7 e(+10) versus 8.1 e(+9)) increased quantities of acetic (P = 0.002) and butyric acids (P < 0.001), and lower (P = 0.03) lactic acid levels in the caeca. At all ages, xylanase treatment reduced (P = 0.04) the proportion of branched chain volatile fatty acids in total SCFA, suggesting a reduction in protein fermentation. These findings suggest that greater degradation of wheat arabinoxylan with xylanase can enhance colonisation of specific bacteria and production of SCFAs in the caeca, an event that may relate to improved broiler performance.