日粮中添加纳豆枯草芽孢杆菌对犊牛消化道发育的影响

Effect of Supplementation of Bacillus subtilis Natto on the Development of Digestive Tract in Calves

本试验旨在研究纳豆枯草芽孢杆菌对犊牛断奶早期和断奶后8周消化道生长发育的影响。选取24头7日龄中国荷斯坦奶牛公犊,随机分为3个处理,每个处理8头犊牛,试验1、2组犊牛分别饲喂Na型和N1型纳豆枯草芽孢杆菌菌液,对照组不饲喂菌液。饲喂的牛奶中添加纳豆枯草芽孢杆菌菌液,连续饲喂直到开食料采食量达到规定要求时断奶;断奶时各组随机选取4头犊牛屠宰,余下4头犊牛继续饲养,8周后屠宰,称胴体重。结果表明,试验1组犊牛断奶早期瘤网胃重量明显高于对照组(P<0.05);试验2组犊牛断奶早期及断奶后8周瘤胃pH显著低于对照组(P<0.05),且与对照组相比,断奶早期皱胃pH显著下降(P<0.05);试验1组犊牛断奶早期及断奶后8周十二指肠长度较对照组相比明显缩短;断奶后8周两处理组犊牛回肠长度显著小于对照组(P<0.05);此外,饲喂纳豆枯草芽孢杆菌还可显著降低犊牛十二指肠和空肠前段食糜的pH(P<0.05)。本试验结果表明,饲喂纳豆枯草芽孢杆菌有利于营养物质消化,促进犊牛生长。

The experiment was conducted to study the effects of Bacillus subtilis Natto on the development of digestive tract in pre-weaning and post-weaning calves.Twenty-four Holstein male calves were used in a complete randomized block design,and was assigned to one of three treatments,8 calves in each group.The calves in the two experimental treatments were fed Na and N1 Bacillus subtilis Natto while no Bacillus subtilis Natto was fed to the calves in the control group.The calves were fed with milk supplemented with the Bacillus subtilis Natto,and starter diet was also fed to the calves until weaning.Four calves in each group were slaughtered randomly at weaning and others were raised until 8 weeks after weaning.All the calves were slaughtered at the end of the trial.The results showed that compared with the control group,the weight of ruminoreticulum in calves fed Na Bacillus subtilis Natto was significantly enhanced（P〈0.05）;but the ruminoreticulum pH-value in the calves from N1 group was decreased throughout the experiment,while that of abomasums was dramatically decreased during the beginning period of weaning（P〈0.05）.The length of the duodenum in the calves fed Na Bacillus subtilis Natto was shorter than the control（P〈0.05）,so was that of the ileum（P〈0.05）.In addition,Bacillus subtilis Natto decreased the pH value in the duodenum and the pre-jejunum.In this study,we found that Bacillus subtilis Natto helped the digestion of the nutrients and promote the health of the calves.