肉鸡和肉鸭消化道食糜的状态特性研究

Physical characteristics of digestive digesta in broilers and ducks

为研究肉鸡和肉鸭各消化道(十二指肠、空肠、回肠、盲肠)食糜状态特性,试验选用体重相似的1日龄肉鸡和肉鸭各120只,分别随机分为10笼,每笼12只进行饲喂,并分别使用普通日粮,试验时间为5 w,之后分别采集各段消化道食糜检测。结果表明:肉鸡和肉鸭盲肠中食糜干物质含量分别高于十二指肠28.9%和10.6%,高于空肠70.7%和19.1%,高于回肠44.3%和9.4%(P <0.05);肉鸡和肉鸭回肠中食糜pH分别高于盲肠8.2%和15.6%(P <0.05);肉鸡盲肠中大肠杆菌含量高于十二指肠20.0%,空肠49.4%,回肠30.3%(P <0.05),盲肠中乳酸菌含量高于十二指肠86.8%,空肠36.1%(P <0.05),肉鸭盲肠中大肠杆菌含量高于空肠66.8%,回肠31.5%(P <0.05),盲肠中乳酸菌高于十二指肠27.1%,空肠63.5%,回肠21.8%(P <0.05);对食糜流变学特性测定发现,各消化道中食糜均表现出黏度随着剪切速率的不断增大先逐渐变小后基本不变的剪切稀化趋势,经过拟合Cross-Williamson模型得到的决定系数R-Sq均大于0.99,具有良好的拟合度。综上,盲肠中的食糜干物质含量最高,pH最低,大肠杆菌和乳酸菌的含量最多,其他消化道间均有不同程度的差异,Cross-Williamson模型零速率黏度α可以表示消化道食糜的流动性能且由大到小依次为盲肠>回肠>空肠>十二指肠,同时消化道食糜均存在剪切稀化的现象。

The characteristics of digesta state in digestive tract(duodenum,jejunum,ileum and cecum)of broilers and ducks are different.A total of 120 one-day-old broilers and ducks with similar body weight were randomly divided into 10 cages,and 12 ducks in each group were fed with ordinary diet.The experiment lasted for 5 w.After that,each section of digestive tract chyme was collected for testing.The results showed as follows:There were significant differences in digesta dry matter content between digestive tract of broilers and ducks(P<0.05),the highest digesta dry matter content was found in caecum,and the lowest was found in jejunum and ileum.The pH of chyme in cecum of broilers and ducks was significantly lower than that of other digestive tracts(P<0.05).The content of Escherichia coli(E.coli)in cecum of broilers was significantly higher than that in other digestive tracts(P<0.05),the content of Lactobacillus in cecum was significantly higher than that in duodenum and jejunum(P<0.05),the content of E.coli in cecum of meat ducks was significantly higher than that in jejunum and ileum(P<0.05),and the content of Lactobacillus in cecum was significantly higher than that in other digestive tracts(P<0.05).The rheological properties of digesta were measured,and it was found that the viscosity of digesta in each digestive tract showed a shear thinning trend with the increase of shear rate.The R-Sq obtained by Cross-Williamson model was greater than 0.99,showing a good fitting degree.In conclusion,the content of chyme dry matter in the cecum was the highest,the pH was the lowest,and the content of E.coli and Lactic acid bacteria was the largest.There were differences in other digestive tract to varying degrees.The zero-rate viscosity of Cross-Williamson modelαcould represent the flow performance of digestive tract chyme,and the order from large to small was cecum>ileum>jejunum>duodenum.At the same time,there was shear thinning of digesta in digestive tract.