载锌凹凸棒石对断奶仔猪肠道免疫功能、食糜挥发性脂肪酸及粪便菌群的影响

Effects of zinc-bearing palygorskite on the intestinal immune function, volatile fatty acid of digesta and fecal microbiota of weaned piglets

旨在研究载锌凹凸棒石(Zn-Pal)对断奶仔猪肠道免疫性能、食糜挥发性脂肪酸(VFA)和粪便菌群含量的影响。选取25日龄体重相近的杜×长×大三元杂交断奶仔猪128头,随机分为4组,每组4个重复,每个重复8头,分别在基础饲粮上添加吉他霉素110 mg/kg+ZnO 2 g/kg(对照组)、吉他霉素55 mg/kg+ZnO 1 g/kg+Zn-Pal 2 g/kg(试验Ⅰ组)、Zn-Pal 2 g/kg(试验Ⅱ组)和Zn-Pal 4 g/kg(试验Ⅲ组)。预试期7 d,正试期28 d。结果表明:1)试验28 d,试验Ⅲ组具有降低粪便中总菌含量趋势(P>0.05);试验Ⅲ组梭菌XIVa和乳酸杆菌含量与对照组差异不显著(P>0.05),但显著高于试验Ⅱ组(P<0.05)。2)除乙酸外,试验Ⅱ组盲肠与结肠食糜中各酸含量均显著低于对照组(P<0.05);试验Ⅲ组盲肠食糜乙酸、丙酸、戊酸和总挥发性脂肪酸含量与对照组差异不显著(P>0.05),其余各酸含量显著低于对照组(P<0.05)。3)试验Ⅲ组肠黏膜中免疫球蛋白A(sIgA)水平与对照组和试验Ⅰ组差异均不显著(P>0.05),但显著高于试验Ⅱ组(P<0.05);试验Ⅲ组回肠黏膜中白细胞介素1β(IL-1β)和转化生长因子-β(TGF-β)水平与对照组和试验Ⅰ组差异均不显著(P>0.05),且TGF-β水平显著高于试验Ⅱ组(P<0.05)。在本试验条件下,4 g/kg Zn-Pal替代饲粮中全部的抗生素对仔猪粪便中各菌群数量、盲肠食糜挥发性脂肪酸含量以及肠道部分免疫指标并无显著影响。因此,载锌凹凸棒石可以作为一种抗生素替代品用于仔猪饲料生产。

This research was conducted to investigate the influence of zinc-bearing palygorskite(Zn-Pal) on the intestinal immunity, the content of volatile fatty acids(VFA) of the digesta and the content of feces microbiota in weaned piglets.A total of 128 25-day-old hybrid weaned piglets with similar weight were used and randomly divided into four groups with four replicates and eight piglets per replicate.The piglets in the control group, experimental groups Ⅰ, Ⅱ and Ⅲ were fed with the basal diet supplemented with 110 mg/kg kitasamycin and 2 g/kg ZnO(Control Group), 55 mg/kg kitasamycin, 1 g/kg ZnO and 2 g/kg Zn-Pal(Group Ⅰ), 2 g/kg Zn-Pal(Group Ⅱ), and 4 g/kg Zn-Pal(Group Ⅲ), respectively.The experiment consisted of a 7 day per-test and a 28 day formal test.The results were as follows:1) At 28 days, the content of total bacteria in the feces of the Group Ⅲ had a decreasing tendency(P>0.05);the contents of Clostridium XIVa and Lactobacillus were of no significant difference between the Group Ⅲ and the Control Group(P>0.05);however, they were significantly higher than those of the Group Ⅱ(P<0.05).2) Except acetic acid, the contents of VFA of caecum and colon digesta in the Group Ⅱ were significantly lower than those in the Control Group(P<0.05).There were no significant difference in the contents of acetic acid, propionic acid, valproic acid and TVFA in caecum digesta between the Group Ⅲ and the Control Group(P>0.05), while the contents of the other VFA were significantly decreased in the Group Ⅲ compared with the Control Group(P<0.05).3) There were no significant differences in the levels of sIgA of intestinal mucosa between the Group Ⅰ, Ⅲ and the control Group(P>0.05), but there were significantly higher than those in the Group Ⅱ(P<0.05).There were no significant difference in the levels of IL-1β and TGF-β of ileum mucosa between the GroupⅢ,the Gruop Ⅰ and the Control Group(P>0.05);however,the level of TGF-β was significantly higher than those in the Group Ⅱ(P<0.05).Under the condition of this erperiment,dietary supplemented of 4 g/kg Zn-Pal replacement of all antibiotics had no significantly effect on the contents of fecal microbiota,the contents of VFA in caecum digesta and the partial intestinal index of piglets.Therefore,Zn-Pal can be used as an antibiotic substitute in piglet feed production.