L-NMMA对鸡球虫早熟弱毒疫苗免疫鸡增重的影响

为了研究鸡球虫早熟弱毒疫苗对免疫鸡增重的影响及一氧化氮合成酶抑制剂(L-NMMA)对免疫鸡增重和免疫效果的影响。取40只SPF雏鸡,分为空白对照组(C1、C2)和单剂量重复接种组(T1、T2),T1、T2组按推荐免疫剂量单剂量重复接种鸡球虫早熟弱毒疫苗,C1和T1、C2和T2分别于二次接种后第7、14天逐只空腹称重,剖检记录十二指肠、空肠和盲肠病变记分,取心脏、肝脏、脾脏、肺脏、肾脏、腺胃、肌胃、十二指肠、空肠和盲肠进行病理组织学检查。另选取40只SPF雏鸡,分为空白对照组C20、攻毒对照组T21、免疫对照组T22和免疫加药组T23,T22和T23按推荐免疫剂量两次免疫鸡球虫早熟弱毒疫苗,T23在免疫的同时腹腔注射L-NMMA,二免后第14天T21、T22和T23均接种鸡球虫混合强毒,测定SPF雏鸡平均增重、相对增重、肠道(十二指肠、空肠和盲肠)病变记分、病变记分减少率(RLS)、血便记分、死亡率及卵囊产量等指标。结果显示,接种组的平均增重显著低于未接种组(P<0.05),接种组的十二指肠、空肠和盲肠有轻微病变且黏膜上皮细胞均有不同程度损伤和脱落;免疫加L-NMMA组一免、二免后及攻毒后试验鸡的平均增重均极显著高于免疫攻毒对照组(P<0.01),且与空白对照组鸡的平均增重无显著差异(P>0.05),且免疫对照组和免疫加药组肠道病变记分和卵囊产量无显著差异(P>0.05)。说明鸡球虫早熟弱毒疫苗对雏鸡肠道有轻微损伤,且对鸡增重有一定影响;L-NMMA可降低鸡球虫早熟弱毒疫苗对试验鸡增重的影响,且不影响疫苗的免疫效果。

Effect of L-NMMA on Weight Gain of Chickens Infected with Chicken Coccidia Premature Attenuated Vaccine

In order to study the effect of chicken coccidia premature attenuated vaccine and nitric oxide synthase inhibitor (L-NMMA) on the weight gain of immunized chicken,and the effect of L-NMMA on immune efficacy.Forty SPF chicks were divided into two blank control groups (C1 and C2) and two single-dose repeated inoculated groups(T1 and T2).In groups T1 and T2,chicks were inoculated repeatedly with the premature attenuated vaccine of chicken coccidia at the recommended single dose,then the chicks with empty stomach were weighted separately on 7th and 14th after the second inoculated.The duodenum,jejunum and cecum lesions were recorded.The heart,liver,spleen,lung,kidney,glandular stomach,muscular stomach,duodenum,jejunum and cecum of the chicks were collected for histopathological examination.Another forty SPF chicks were divided into blank control group (C20),challenge control group (T21),immune control group (T22) and immune with drug group (T23).In groups T22 and T23,chicks were vaccinated twice with premature attenuated vaccine at the recommended immune dose,and the chicks in T23 group were injected with L-NMMA at the same time.On the 14th after the second immune,the chicks were gavaged with mixed virulent chicken coccidia,then the average weight gain,relative weight gain,intestonal (duodenun,jejunum and cecum) lesion scores,reduction of lesion scores (RLS),bloody stool scores,mortality and oocyst production were measured.The results showed that the average weight gain of the vaccinated group was significantly lower than the unvaccinated group (P<0.05).The duodenum,jejunum and cecum of the vaccinated group had mild lesions and the mucosal epithelial cells had different degrees of damage and shedding.The average weight gains of the vaccinated with L-NMMA group after the first,second immuned and challenged were all extremely significantly higher than the immune-challenged control group (P<0.01),while the average weight gain was not significantly different with the blank control group (P>0.05),and there were no significant differences in intestinal lesion score and oocyst yield between immune control group and drug immune group (P>0.05).The results demonstrated that premature attenuated vaccine of chicken coccidia had light damage to the intestines of the chicks and had certain negative effects on the weight gain.In addition,L-NMMA could reduce the vaccine’s adverse effect on the weight gain and had no effect on the immune efficacy.