玉米烯酮与氟苯尼考对雏鸡免疫功能和生长性能的影响

The Effect of Zearalenone and Florfenicol on Immune Function and Growth Performance of Chicks

玉米烯酮(zearalenone,ZEN)为常见的环境污染物,而氟苯尼考(florfenicol,FFC)则是兽医临床上应用非常广泛的抗菌药,二者极有可能同时暴露,对动物产生毒副作用,但目前尚未见相关研究报道。为探究ZEN和FFC单独与共同暴露对雏鸡生长性能和免疫功能的影响,将40只1日龄雏鸡适应性饲养2 d,于3日龄时随机分为4组,每组10只,公母各半,分别为对照组、ZEN组(按1 mg·kg^(-1)日粮剂量染毒ZEN 21 d)、FFC组(按100 mg·L^(-1)饮水给药FFC,连续5 d)和ZEN+FFC组(按1 mg·kg^(-1)日粮连续染毒ZEN 21 d的同时,前5 d连续按治疗剂量100 mg·L^(-1)饮水给药FFC),试验周期为21 d。测定雏鸡的平均日增重、脏器指数和料重比,并采用ELISA试剂盒检测血清中细胞因子和新城疫抗体水平。结果表明,即使是低水平的ZEN也可抑制白细胞介素-2(IL-2)和干扰素-γ(IFN-γ)的分泌从而抑制雏鸡免疫功能,并可能通过促进白细胞介素-1(IL-1)、白细胞介素-6(IL-6)和肿瘤坏死因子-α(TNF-α)的释放诱发炎症反应;早期使用治疗剂量的FFC不仅可抑制雏鸡的生长,还能使IL-2和IFN-γ分泌下调从而产生免疫抑制。二者共同暴露虽然可减轻其对IL-2和IFN-γ的抑制作用,并控制玉米烯酮诱导的炎症反应,但可抑制雏鸡的体液免疫应答水平。因此,应加强雏鸡饲料中ZEN污染的监控,慎重使用FFC作为开口药,尽量避免在二者同时存在时对雏鸡进行疫苗接种,以防免疫失败。

Zearalenone(ZEN)is a common environmental pollutant,while florfenicol(FFC)is a very widely used antimicrobial drug in veterinary clinic.They are highly likely to be exposed at the same time and have toxic and side effects on animals,but no relevant studies have been reported.To investigate the effects of single and combined exposure to ZEN and FFC on growth performance and immune function of chicks,forty 1-day-old chicks were adaptively fed for 2 days,then they were randomly divided into 4 groups with 10 chicks(half male and half female)in each group.The chicks in Control group were fed with a basal diet,and those in ZEN group were poisoned by gavage with dose of 1 mg·kg^(-1) diet for 21 days,those in FFC group were treated by water administration with 100 mg·L^(-1) drinking water for the first 5 days,while those in ZEN+FFC group were poisoned by gavage with dose of 1 mg·kg^(-1) diet for 21 days and treated by water administration with 100 mg·L^(-1) drinking water for the first 5 days.The experiment lasted 21 days.The average daily gain,organ index and feed to gain ratio of chicks were measured.Serum levels of cytokines and Newcastle disease antibody were detected by ELISA kit.The results showed that although ZEN was at low pollution level,it could inhibit the secretion of IL-2 and IFN-γ,thereby inhibiting immune function of chicks,and might induce inflammatory response by promoting the release of IL-1,IL-6 and TNF-α.Early treatment of FFC could not only inhibit the growth of chicks,but also down-regulate the secretion of IL-2 and IFN-γ,resulting in immunosuppression.The combined exposure to ZEN and FFC mitigated their inhibition to IL-2 and IFN-γand controlled inflammatory responses induced by ZEN,however,it also inhibited the humoral immune response of chicks.Therefore,the monitoring of ZEN contamination in the feed of chicks should be enhanced.FFC should be cautiously used for health protection drugsin chicks since they were born.In addition,vaccination should be avoided when chicks were exposed to both ZEN and FFC in order to prevent the failure of immunization.