【摘要】 以相对增重率(RBWG)、饲料转化率(FCR)和盲肠相对卵囊产量(ROP)为指标,评价了1次或2次分别以1×103个或3×103个毒害艾美耳球虫(E.necatrix)孢子化卵囊(SO)/鸡剂量免疫接种后特异性免疫力的产生和持续时间。笼养岭南黄肉雏鸡于3日龄1次或3日龄和10日龄2次分别接种不同剂量的E.necatrix SO后,于17日龄(2次免疫组为24日龄)、34日龄和50日龄时以14×104SO/鸡剂量的同源卵囊攻虫,结果表明,免疫后2周卵囊接种鸡已产生坚强免疫力,1次免疫接种者(17日龄)高、低2个不同剂量组的RBWG、FCR和ROP分别为95.5%、2.32、24.54%和101.4%、2.32、21.1%;而2次免疫组(24日龄)的上述指标则分别为106.5%、2.44、9.3%和98.2%、2.38、7.48%。至34日龄和50日龄攻虫时,这些指标均有不同程度的下降,且随着时间延长,下降更为明显,但2次免疫处理组的这些指标均明显优于1次免疫者;同一次处理的不同剂量组间无明显差异。结果揭示,雏鸡口服免疫接种一定剂量的E.necatrix孢子化卵囊后可迅速诱导鸡体特异性免疫力的产生,但免疫保护力在笼养条件下持续时间较短。更多还原

【Abstract】 The immunoprotection induced by the sporulated oocysts of Eimeria necatrix vaccination in the single dose of 1(low) or 3(high)×103 at 3 day-old or dual doses of 1 or 3×103 at 3-and 10-day-old were evaluated with the parameter of relative body weight gain(RBWG),feed conversation rate(FCR) and relative cecal oocyst production(ROP).The caged vaccinated chickens were challenged using E.necatrix sporulated oocysts with a dose of 14×104 at 17(single dose)-or 24(dual dose)-day-old,34-and 50-day-old,respectively.The results showed that the specific immunity to the challenged E.necatrix could be produced 2 weeks post immunization.The parameters of RBWG,FCR and ROP in the single dose treatment with low vaccinated dose were 95.5%,2.32 and 24.54%,vs. 101.4%,2.32 and 21.1% in high immunized dose group challenged at 17-day-old.The better immunoprotection could be found in the treatment with dual vaccination at low or high dose.The parameters were 106.5%,2.44 and 9.3% in low dose treatment and 98.2%,2.38 and 7.48% in high dose treatment when challenged at 24-day-old,respectively.All the parameters reduced as the challenged day-old was postponed,but higher immunoprotection was observed in the groups with dual doses vaccination.更多还原