木聚糖酶在提高饲喂小麦日粮的肉仔鸡的生长性能和肠道健康中起关键作用。然而,关于添加木聚糖酶对肉鸡回肠微生物群的影响的知识是有限的。选择总共128只1日龄肉鸡(初始BW48.03±0.33g),以研究木聚糖酶(AT-xynA)对生长性能的影响,回肠形态,微生物群组成,免疫反应,抗氧化能力,和肉鸡的内分泌肽水平。肉鸡被随机分配到两种饮食处理(n=8),即,小麦-大豆基础日粮和含4,000U/kgAT-xynA(XY)的基础日粮。在第7、14、21和42天,对肉鸡称重并对回肠组织取样。在第21天和第42天收集回肠消化物样品用于分析微生物群组成。结果表明,AT-xynA可以提高平均日增重和平均日采食量,日粮与日龄之间存在交互作用(p<0.05)。在第21天和第42天,添加木聚糖酶会降低回肠微生物群α-多样性,以及潜在致病微生物群的相对丰度,比如变形细菌门,Moraxellaceae和葡萄球菌科,葡萄球菌属,假单胞菌,链球菌,和肠球菌,增加了乳酸菌的丰度(p<0.05)。此外,在XY组肉鸡中,乙酸盐浓度和短链脂肪酸产生菌的丰度也降低(p<0.05)。AT-xynA增加回肠绒毛高度,胰高血糖素样肽-1和胰岛素样生长因子-1浓度和减少的白细胞介素-1β,白细胞介素-6,肿瘤坏死因子-α,肉仔鸡的丙二醛含量,这些对肠道健康的积极影响在年轻肉鸡中更大。总之,以小麦为基础的日粮中添加木聚糖酶可以改善回肠肠形态和免疫功能,缓解细菌的过度发酵,这可能与肠道微生物群的变化有关。此外,木聚糖酶对幼龄肉鸡肠道健康的积极作用更为明显,从而有助于肉鸡生长性能的后续改善。
Xylanase exerts key roles in improving growth performance and intestinal health of broilers fed wheat-based diets. However, knowledge is limited regarding effects of xylanase supplementation on
ileal microbiota in broilers. A total of 128 one-day-old broilers (initial BW 48.03 ± 0.33 g) were selected to investigate effects of xylanase (AT-xynA) on growth performance,
ileal morphology, microbiota composition, immune response, antioxidant capacity, and endocrine peptide levels in broilers. Broilers were randomly allotted into two dietary treatments (n = 8), namely, a wheat-soybean basal diet and a basal diet with 4,000 U/kg AT-xynA (XY). On days 7, 14, 21, and 42, broilers were weighted and
ileal tissues were sampled.
Ileal digesta samples were collected for analyzing microbiota composition on days 21 and 42. The results showed that AT-xynA could improve average daily weight gain and average daily feed intake, and there were interactions between diet and age of broilers (p < 0.05). On days 21 and 42, xylanase supplementation decreased
ileal microbiota α-diversity, and the relative abundance of potentially pathogenic microbiota, such as phylum Proteobacteria, family Moraxellaceae and Staphylococcaceae, genus Staphylococcus, Pseudomonas, Streptococcus, and Enterococcus, increased the abundance of Lactobacillus (p < 0.05). Moreover, the reduction in acetate concentration and abundance of short-chain fatty acid-producing bacteria was also observed in broilers from XY group (p < 0.05). AT-xynA increased ileal villus height, glucagon-like peptide-1, and insulin-like growth factor-1 concentrations and decreased interleukin-1β, interleukin-6, tumor necrosis factor-α, and malondialdehyde content in broilers, and these positive effects on intestinal health were greater in young broilers. In conclusion, xylanase supplementation to wheat-based diets could improve ileal intestinal morphology and immune function, and alleviate excess fermentation of bacteria, which may be related to changes of intestinal microbiota. In addition, the positive effects of xylanase on intestinal health were more pronounced in young broilers, thus contributing to subsequent improvement in growth performance of broilers.