| 摘要: |
| 【目的】研究蛋鸡饲粮中添加不同水平的碳酸氢钠对肠道内容物pH、消化蛋白酶活性和肠道菌群的影响，以探讨饲粮中添加碳酸氢钠对蛋鸡消化机能的影响。【方法】选取21周龄海兰褐壳蛋鸡450只，随机分为5组，每组6个重复，每重复15只鸡；对照组饲喂基础饲粮，试验组分别饲喂添加0.1%，0.5%，2.5%，5% NaHCO3的试验饲粮，试验期133 d。试验期末采集各组肌胃、十二指肠、空肠、回肠、盲肠食糜及粪便，测定各段食糜和粪便的pH、肌胃食糜的胃蛋白酶活性、十二指肠食糜的胰蛋白酶和糜蛋白酶活性以及回肠和盲肠食糜中菌群的变性梯度凝胶电泳（DGGE）指纹图谱，并计算回肠、盲肠食糜的多样性指数和相似性指数。【结果】1）饲粮中添加0.1%和0.5%的碳酸氢钠对蛋鸡肠道各段pH无显著影响，而饲粮中添加2.5%和5%的碳酸氢钠可显著提高蛋鸡肌胃、十二指肠和空肠内容物以及粪便的pH(P＜0.05)。2）饲粮中添加2.5%和5%的碳酸氢钠可显著降低肌胃中胃蛋白酶、十二指肠中胰蛋白酶和糜蛋白酶活性(P＜0.05)。3）饲粮中添加碳酸氢钠可改变蛋鸡回肠和盲肠的微生物多样性指数。【结论】饲粮中添加高剂量的碳酸氢钠(2.5%和5%)显著影响蛋鸡消化道内环境，降低蛋鸡的蛋白消化机能。 |
| 关键词: 碳酸氢钠 蛋鸡 肠道pH 蛋白酶活性 肠道菌群 |
| DOI： |
| 分类号: |
| 基金项目:国家蛋鸡产业技术体系建设专项（CARS-41-K16） |
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| Effects of dietary sodium bicarbonate on digesta pH,digestive enzyme activities and intestinal microflora of laying hens |
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LIU Yan,DONG Xiao-fang,TONG Jian-ming,et al
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| Abstract: |
| 【Objective】The study investigated the effects of dietary sodium bicarbonate on intestinal pH,digestive proteases activities and intestinal microflora of laying hens to discuss the effects of dietary sodium bicarbonate on digestive function of laying hens.【Method】450 21-week-old Hi-line brown layers were randomly allocated into 5 groups.Each group had 6 replicates and each replicate had 15 hens.Laying hens in control group were fed with basal diet.The trial groups were fed with the basal diets supplemented with 0.1%,0.5%,2.5% and 5% sodium bicarbonate,respectively.The experiment last 133 days.The digesta in gizzard,duodenum,jejunum ileum,and cecum,and manure were collected at the end of experiment.pH values of manure and digesta in each gastrointestinal tract section and the activities of pepsin in gizzard,trypsin and chymotrypsin in duodenum were measured respectively.Ileal and cecal microflora were analyzed with DGGE fingerprint method and the Shannon-Weiner index and similarity index were calculated.【Result】1) pH in each section of gastrointestinal tract were not affected significantly by the supplement of 0.1% or 0.5% sodium bicarbonate whereas 2.5% or 5% sodium bicarbonate supplementary increased pH of digesta in gizzard,duodenal,and jejunal and pH of manure significantly (P＜0.05).2) Activities of pepsin in gizzard and trypsin and chymotrypsin in duodenum were decreased significantly by the supplement of 2.5% or 5% sodium bicarbonate (P＜0.05).3) Ileal and cecal microflora Shannon-Wienner indiex were altered by the supplement of 2.5% or 5% sodium bicarbonate.【Conclusion】Higher levels of sodium bicarbonate (2.5% and 5%) in diet decreased protein digestive function and changed normal intestinal ecological conditions of laying hens. |
| Key words: sodium bicarbonate laying hens intestinal pH protease activities intestinal microflora |
