包膜丁酸钠对球虫感染兔的影响研究

Effect of coated sodium butyrate against coccidium infection in rabbit

为研究日粮中添加包膜丁酸钠对家兔球虫病的影响。本研究选用35日龄健康、断奶实验兔,随机分为5个组。分别饲喂3种不同日粮,Ⅰ组和Ⅲ组为基础日粮对照组,Ⅱ组和Ⅳ组在基础日粮的基础上添加500 mg/kg包膜丁酸钠,Ⅴ组在基础日粮的基础上添加40 mg/kg托曲珠利。于试验第28 d,分别给予Ⅲ、Ⅳ、Ⅴ组实验兔口服接种5×10^5个大型艾美尔球虫孢子化卵囊,攻毒后10 d进行粪便球虫卵囊计数,攻毒后12 d采样,进行肠道形态以及相关寄生虫免疫指标的检测。结果显示：Ⅰ组实验兔的克粪便卵囊数（OPG）显著高于Ⅱ组（p〈0.05）;Ⅲ组的OPG显著高于其它各组（p〈0.05）。空肠、回肠绒隐比（V/C）,Ⅱ组显著高于Ⅰ组（p〈0.05）,Ⅳ组显著高于Ⅲ组（p〈0.05）。空肠、回肠IFN-γ水平,Ⅱ组显著低于Ⅰ组（p〈0.05）,Ⅳ组显著高于Ⅲ组和Ⅴ组（p〈0.05）。Ⅳ组空肠IL-2水平显著高于Ⅲ组（p〈0.05）。Ⅳ组血清可溶性CD4分子水平显著高于Ⅰ组（p〈0.05）。研究表明包膜丁酸钠能够提高家兔抵抗球虫感染的能力。

The aim of this study was to investigate the effect of ration containing coated sodium butyrate on rabbit coccidiosis. The weaning rabbits of 35 days old were randomly divided into five groups. Group Ⅰ and Ⅲ were control groups in which the rabbits were fed with basal ration. Coated sodium butyrate （500 mg/kg） was added into basal ration in group Ⅱ and Ⅳ. Toltrazuril （40 mg/kg） was added into basal ration in group V. On day 28, the rabbits in group Ⅲ, Ⅳ and Ⅴ were oral vaccination with 5×10^5 sporulated oocysts of Eimeria magna. Oocysts in the faeces were counted 10 days after challenge. The intestinal morphology and related immune indexes were detected when sampling 12 days following challenge. The results showed that oocyst per gramme of faeces （OPG） in group I was significantly higher than that in group Ⅱ （p〈0.05） and OPG in group Ⅲ was the highest among groups （p〈0.05）. The ratio of villus and cryptin （V/C） in group Ⅱ was significantly higher than that in group Ⅰ, and that in group Ⅳ was significantly higher than that in group Ⅲ （p〈0.05）. The IFN-γ level of jejunum and ileum in group Ⅱ was significantly lower than that in group Ⅰ （p〈0.05）, and that in group Ⅳ was significantly higher than that in group Ⅲ and V （p〈0.05）. The IL-2 level of jejunum in group Ⅳ was significantly higher than group Ⅲ （p〈0.05）. Moreover, the level of soluble CD4 in serum was higher in group Ⅳ than that in group Ⅰ （p〈0.05）. These findings indicate that coated sodium butyrate were able to improve the ability of rabbit against coccidial infection .