柔嫩艾美耳球虫毒害艾美耳球虫变位艾美耳球虫交叉免疫试验

柔嫩艾美耳球虫毒害艾美耳球虫变位艾美耳球虫交叉免疫试验黄兵，赵其平，何林华，吴薛忠，陈兆国，史天卫（中国农科院上海家畜寄生虫病研究所，２００２３２）鸡感染球虫后会产生一种抵抗再次感染的免疫反应，这种免疫反应具有种的特异性，即感染某种球虫不能保护抵抗另...     

鸡球虫病四价活疫苗对毒害艾美耳球虫和柔嫩艾美耳球虫的免疫效果观察

为评价一种商品化鸡球虫病四价活疫苗[柔嫩艾美耳球虫(E.tenella)、毒害艾美耳球虫(E.necatrix)、巨型艾美耳球虫和堆型艾美耳球虫]对E.necatrix和E.tenella的免疫保护效果,本研究基于试验鸡血便记分、存活率、相对增重率、病变值、卵囊值及抗球虫指数(ACI)等指标对其免疫效果进行检测.结果表明,免疫攻虫组抗E.necatrix和E.tenella的ACI分别为157.3和135.6,均低于160,表明该球虫疫苗抗两种球虫的效果均为低效.然而,免疫攻虫组鸡血便数量、血便记分、增重、卵囊产量和病变记分等指标均优于阳性对照组.综合指标显示,该疫苗对E.necatrix和E.tenella具有一定的免疫保护力,但单纯采用疫苗并不能够达到防控鸡球虫病的目的.     

鸡柔嫩艾美耳球虫和巨型艾美耳球虫双重PCR检测方法的建立

为了建立一种能够快速实现对鸡柔嫩艾美耳球虫(Eimeria tenella)和巨型艾美耳球虫(E.maxima)同时进行检测的双重PCR方法,基于2种艾美耳球虫各自的ITS-1基因筛选2对特异性引物,对制备的阳性DNA样品进行PCR扩增,凝胶电泳检测结果显示,分别在约450bp和150bp处出现目的条带。对PCR反应中的退火温度、MgCl2浓度、DNA模板量等进行优化。结果表明,当退火温度为59℃、MgCl2浓度为2.5mmol/L、DNA模板量为2μL时,双重PCR扩增结果最佳。特异性检测结果显示,所建立的双重PCR对环形泰勒虫、羊巴贝斯虫、隐孢子虫和蓝氏贾第虫的扩增结果均呈阴性,表明建立的方法具有较高的特异性。成功建立了柔嫩艾美耳球虫和巨型艾美耳球虫双重PCR检测方法,为临床中鸡球虫病的快速诊断提供了一种可靠的检测方法。     

鸡胚接种柔嫩艾美耳球虫和堆形艾美耳球虫活卵囊的免疫保护试验

给18日龄鸡胚接种一定剂量的柔嫩艾美耳球虫(Eim eria tenella)和/或堆形艾美耳球虫(E.acervulina)孢子化卵囊,出雏后在无球虫环境中笼养,1~10日龄每天收集各组粪便样本,计数克粪便卵囊数(OPG),并于14日龄时以大剂量同源孢子化卵囊攻虫,以相对增重率(RWG)、饲料转化率(FCR)、相对卵囊产量(ROP)评价免疫保护效果。结果显示,以E.tenella或E.acervulina卵囊免疫18日龄鸡胚,其卵囊排出的潜隐期及达到峰值的时间与1日龄雏鸡接种组相一致,有相似的排卵囊曲线,提示其诱导免疫的建立是在出雏后开始建立的。攻虫后各免疫组的RWG由攻虫对照组的31.9%~51.7%提高到了76.5%~83.6%,RCR由攻虫对照组的4.11~4.89改善为2.72~2.96,ROP降至4.7%~23.5%。结果表明以一定剂量E.tenella和E.acervulina卵囊单独或混合经羊膜腔免疫18日龄鸡胚都可以建立起针对出雏后14日龄同源攻虫的良好免疫保护力。比较混合免疫E.tenella和E.acervulina卵囊组与单一接种E.tenella或E.acervulina卵囊组的免疫效果发现,混合免疫组的各项指标均稍优于后者。     

柔嫩艾美耳球虫洛阳分离株的致病性研究

利用人工感染试验,研究柔嫩艾美耳球虫洛阳分离株的致病性。结果表明,随着感染剂量的提高,其死亡率上升,平均增重下降、平均病变记分提高,半数致死量(LD50)为3.248 7×104个/只。为洛阳地区防控其柔嫩艾美耳球虫所病提供了依据。     

五种不同地理株柔嫩艾美耳球虫免疫保护性比较

用五个不同地理株的柔嫩艾美耳球虫（Eimeria tenella），即：广州株、保定株、长春株、北京株、沈阳株，对12日龄雏鸡分别进行免疫攻虫。通过OPG计数，粪便计分，盲肠病变计分，增重测定，计算保护率。结果发现不同地理株球虫的免疫保护率有明显差异，广州株80．2％〉保定株73．2％〉长春株68．4％〉北京株63．8％〉沈阳株51．0％。其中广州株比其他虫株有显著保护率（P〈0．01）。免疫后的雏鸡抽血进行CD4^＋、CD8^＋T细胞检测，结果各株均能引起两种T细胞数量增加，表明CD4^＋、CD8^＋T细胞在球虫免疫中起着重要作用。     

柔嫩艾美耳球虫YL株抗药性研究

用柔嫩艾美耳球虫杨凌株 ( YL t)对 1 4日龄雏鸡进行感染 ,检测了该虫株对 4种常用抗球虫药 (马杜拉霉素、地克珠利、克球粉和氯苯胍 )的敏感性。以最适抗球虫活性百分率、抗球虫指数、相对卵囊产量和病变记分减少率为指标 ,进行综合评定 ,其抗药程度分为无抗药性、轻度抗药性、中度抗药性和完全抗药性 4个等级。结果表明 ,该虫株对马杜拉霉素有轻度抗药性 ,对地克株利有完全抗药性 ,对克球粉和氯苯胍无抗药性。     

屎肠球菌对感染柔嫩艾美耳球虫肉鸡生长性能和肠道屏障的影响

旨在探究屎肠球菌(Enterococcus foecium)对人工感染柔嫩艾美耳球虫(Eimeriatenella)肉鸡生长性能、存活率、盲肠损伤、粪便卵囊排出和肠道屏障功能的影响.选取体重相近的1日龄肉鸡(罗斯308)180羽,随机分为5组,包括空白对照组(NC)、感染对照组(PC)、70 mg·kg-1盐霉素添加组...     

8301多糖配合柔嫩艾美耳球虫诱导雏鸡保护性免疫的研究

本文观察了８３０１多糖对鸡柔嫩艾美耳球虫活卵囊免疫效力的影响。结果表明，８３０１多糖配合鸡柔嫩艾美耳球虫活印囊免疫雏鸡后７天，应用强毒攻击，雏鸡存活率为１００％，增重率为７１．０７％，抗球虫指数为１７０．５５。单用柔嫩艾美耳球虫活卵囊免疫的雏鸡存活卒、增重率及抗球虫指数分别为６６．７％、４６．２７％及１１４．９３。在明８３０１多糖能增强鸡球虫免疫的效力。     

柔嫩艾美耳球虫病毒的鉴定

鸡球虫病是由艾美耳属（Eimeria）的一种单细胞寄生性原虫引起的严重危害养禽业发展的重要疾病之一,遍及世界各地。感染鸡的艾美耳属球虫中,国外已报道在巨型艾美耳球虫（E.maxima）,堆型艾美耳球虫（E.acervu-lina）,毒害艾美耳球虫（E.necatrix）和布氏艾美耳球虫（E.brunetti）中发现了病毒粒子或病毒RNA。但是作为危害最严重的柔嫩艾美耳球虫是否有病毒感染,国内外迄今尚无报道。本研究首次在柔嫩艾美耳球虫中发现病毒并对其进行了鉴定。通过核酸分析、RNA依赖的RNA聚合酶（RDRP）活性和电镜形态观察对病毒进行鉴定。核酸酶的敏感性试验结果表明在柔嫩艾美耳球虫总核酸电泳图谱上观察到的大小分别为1.4、2.4和3.6kb的3条病毒带均不能被DNA酶（100mg/L）降解,但可被RNA酶（1.0mg/L）降解,表明这些核酸为RNA。另外,这些核酸不能被高盐浓度（0.3mol/L NaCl）RNase A（10mg/L）降解,但可被低盐浓度（0.015mol/L NaCl）RNase A（10mg/L）降解,并且采用α-32P标记的UTP掺入法测得该病毒样核酸具有RNA依赖RNA聚合酶（RDRP）活性,表明这些核酸为双链RNA（dsRNA）。利用蔗糖梯度离心和透射电镜技术对柔嫩艾美耳球虫病毒进行了分离和鉴定。电镜负染观察到柔嫩艾美耳球虫病毒粒子外观呈球形,二十面体,无囊膜,直径38nm。     

妥曲珠利对肉鸡生长性能和免疫机能的影响

本试验旨在研究饮水中添加不同水平妥曲珠利对肉鸡生长性能和免疫机能的影响.288只1日龄AA肉仔鸡,随机分为4组.各组日粮相同,对照组(1组)饮用自来水,试验组(2组、3组和4组)于8～10日龄连续3d饮水中分别添加妥曲珠利25mg/L、50 mg/L和100 mg/L,试验期42 d.结果表明,妥曲珠利对肉鸡生长性能和血清新城疫抗体效价均无显著影响(P＞0.05);25mg/L和50 mg/L妥曲珠利组肉鸡28日龄胸腺指数和脾脏指数显著高于对照组(P＜0.05),100mg/L妥曲珠利组肉鸡28日龄腔上囊指数显著低于对照组(P＜0.05);50 mg/L妥曲珠利组外周血T淋巴细胞的转化率显著高于对照组(P＜0.05).可见,饮水中添加25 mg/L和50 mg/L妥曲珠利对肉鸡免疫机能有一定促进作用.     

早期饲喂对肉仔鸡生产性能和免疫器官发育的影响

选择刚出壳的AA肉仔鸡200只,随机分成2组,每组设4个重复,每个重复25只鸡,进行饲养试验.早期饲喂组在出壳3 h饲喂超前期日粮,早期禁食组在出壳48 h后饲喂常规肉雏鸡日粮.早期饲喂组于6日龄全部换为常规日粮.在试验的第21、42、49日龄称重、翅静脉采血,研究早期饲喂对生产性能、血清尿素氮和新城疫(NDV)抗体水平的影响.在21、42日龄采用收粪法分别进行2次代谢试验,测定氮沉积率.在试验结束时,进行屠宰试验,研究早期饲喂对胸肌率和免疫器官指数的影响.结果表明:(1)早期饲喂能显著的提高肉仔鸡各阶段的平均体质量(P＜0.05),0～21日龄鸡的氮沉积率显著高于早期禁食组(P＜0.05),血清尿素氮显著低于早期禁食组(P＜0.05),死亡率降低6%.(2)早期饲喂组鸡的免疫器官指数显著的大于早期禁食组(P＜0.05),并显著的提高了NDV抗体水平.(3)早期饲喂对胸肌率和腿肌率有显著的影响,与早期禁食组相比,胸肌率提高了2.14%而腿肌率下降了0.93%.     

Effect of dietary supplementation with oregano essential oil on performance of broilers after experimental infection with Eimeria tenella.

A study was carried out to examine the effect of dietary supplementation of oregano essential oil on performance of broiler chickens experimentally infected with Eimeria tenella at 14 days of age. A total of 120 day-old Cobb-500 chicks separated into 4 equal groups with three replicates each, were used in this study. Two groups, one infected with 5 x 10(4) sporulated oocysts of E. tenella and the other not, were given a basal diet and served as controls. The other two groups also infected with E. tenella were administered diets supplemented with oregano essential oil at a level of 300 mg/kg, or with the anticoccidial lasalocid at 75 mg/kg. Following this infection, survival rate, bloody diarrhoea and oocysts excretion as well as lesion score were determined. Throughout the experimental period of 42 days, body weight gain and feed intake were recorded weekly, and feed conversion ratios were calculated. Two weeks after the infection with E. tenella supplementation with dietary oregano oil resulted in body weight gains and feed conversion ratios not differing from the non-infected group, but higher than those of the infected control group and lower than those of the lasalocid group. These parameters correspond with the extent of bloody diarrhoea, survival rate, lesion score and oocyst numbers and indicated that oregano essential oil exerted an anticoccidial effect against E. tenella, which was, however, lower than that exhibited by lasalocid.     

Effect of dietary Lycium barbarum polysaccharide on growth performance and immune function of broilers

Lycium barbarum polysaccharide (LBP) is a traditional Chinese herbal medicine possessing many properties such as anti-oxidant and immunomodulation. This study was conducted to evaluate the clinical efficacy of LBP in broilers. A total of 240 newly hatched broilers were randomly allotted into 4 treatments with 6 replicates. Diets in 3 treatment groups were supplemented with 2, 4, and 8 g/kg LBP, respectively, based on the control diet. Lymphocytes isolated from broiler blood were used to detect immunoregulation function of LBP in vitro. Results in vivo showed that average daily feed intake (ADFI) and feed conversion ratio (FCR) in the 4 g/kg LBP group were decreased significantly (P < 0.05). Dietary 4 g/kg LBP significantly increased immune organ indexes of broilers at 21 d (P < 0.05). Moreover, levels of serum total protein, globulin, albumin, and lysozyme of broilers were higher in the 8 g/kg LBP group (P < 0.05). CD4⁺/CD8⁺ ratio in blood T cells was higher in the 4 g/kg LBP group (P < 0.05). Results in vitro suggested that 100 and 1,600 μg/mL LBP supplementation significantly promoted blood B and T lymphocyte proliferation of broilers, respectively (P < 0.05). TNF-α mRNA abundance was observably decreased in the lower LBP concentration groups (P < 0.05). In conclusion, LBP may possess the clinical efficacy for growth promotion and immunomodulation and could be used as an alternative for nutritive additive in broilers.     

Influence of low levels of dietary aflatoxins on Eimeria tenella infections in broilers

The present study was conducted to evaluate the adverse effects of an interaction between low levels of dietary aflatoxins (AF) and Eimeria tenella infection on broiler chicks. A set of 1-day-old chicks were raised for 35 days in the following groups: a control group, a group fed AF, a group fed AF and inoculated with E. tenella (AF + E.ten), and a group inoculated with E. tenella alone. AF in the contaminated diet were given at 200 ppb starting from the seventh day after hatching while E. tenella was inoculated at a dose of 5 × 10⁴ sporulated oocysts per chick at the 14th day after hatching. Worsened performance traits and high mortality were all observed in the treated birds, particularly the AF + E.ten group. Lesion scores and oocyst outputs were not different within groups. Chickens fed with AF had significantly increased serum ALT and ALP activities as well as decreased albumin content. They also showed hepatomegaly, hepatocytic vacuolation and necrosis, an atrophied bursa of Fabricius, and a thymus with tissue depletion. E. tenella-infected broilers displayed a significant reduction in packed cell volume, hemoglobin content and lymphocyte percentage, and showed hemorrhagic typhlitis. The deficits in hepatic function and hematologic parameters as well as the gross pathological, and histopathological changes, were more common and more severe in the group that was exposed to both aflatoxicosis and coccidiosis than in the groups exposed to either treatment alone. Thus, the combination of aflatoxicosis and E. tenella infection may influence the course of coccidial infection due to additive effects.     

发酵亚麻籽饼对肉鸡生长性能、免疫及抗氧化功能的影响

试验旨在研究发酵亚麻籽饼对肉鸡生长性能、抗氧化功能及免疫功能的影响.选取180只1日龄健康、体重约为(46.37±1.09)g的爱拔益嘉肉鸡,随机分为3组,每组6个重复,每个重复10只鸡.试验分为两个阶段:前期(1～21 d)和后期(22～42 d).对照组(CON组)饲喂玉米-豆粕型日粮,试验组分别在基础日粮中添加5...     

壳聚糖对肉仔鸡生长性能与免疫功能的影响

将120只1日龄爱拔益加(AA)肉仔鸡随机分成5组,每组3个重复,每重复8只鸡。对照组(Ⅰ)喂给基础日粮,试验组(Ⅱ、Ⅲ、Ⅳ、Ⅴ)分别在基础日粮中添加10、20、30g/kg壳聚糖和5mg/kg黄霉素,试验期3周。试验结果表明:肉仔鸡日粮中添加10g/kg壳聚糖能够不影响其生长性能,而添加量增大到20g/kg和30g/kg,严重影响肉仔鸡生长性能。添加壳聚糖不能提高日粮营养物质的利用率但能提高肉仔鸡免疫功能。     

The effect of subclinigal infections with Eimeria praecox and Eimeria tenella on pigmentation and vitamin a absorption in broilers

Broilers were fed for the first 5 weeks on a starter ration containing 20 g of xanthophylls/ton. They were then divided into uniform groups and fed on either a broiler finisher ration supplying 30 g xanthophylls/ton or one supplying 20 g xanthophylls/ton and supplemented with 2.5 g canthaxanthin/ton. Six groups from each dietary regime were given 10,000 sporulated oocysts of E. praecox, daily for 5 d, six with 5000 sporulated oocysts of E. tenella daily for 5 d while the remaining six groups served as uninfected controls. All birds were housed in cages with solid floors to aid in recycling the infections over the 3‐week test period.

The resulting subclinical E. praecox and E. tenella infections, regardless of dietary treatment, caused slightly reduced weight gains and slightly impaired food conversions. Shank and breast skin visual scores, plasma and toe‐web carotenoids and liver vitamin A levels were not depressed as a result of either coccidial infection.     

糖肽酮萜素对肉仔鸡生产性能、免疫器官和血液生化指标的影响

选1日龄艾维茵肉仔鸡600只,随机分成3组(每组4个重复,每个重复50只)。空白对照组饲喂基础日粮(无抗生素添加剂),抗生素对照组饲喂基础日粮+380mg/kg金霉素,试验组饲喂基础日粮+500mg/kg糖肽酮萜素,试验期为49d。饲养试验结果表明:在1～49日龄期间,试验组比空白对照组、抗生素对照组的肉仔公鸡平均日增重分别提高了17.42%(P<0.05)、0.92%(P>0.05);而料肉比分别降低了6.06%(P<0.05)、1.06%(P>0.05)。对于肉仔母鸡,与空白对照组相比,试验组日增重提高了12.68%(P<0.05),料肉比降低了7.21%(P<0.05);日增重及料肉比比抗生素对照组略低,但差异不显著(P>0.05)。试验结果还表明,饲料中添加糖肽酮萜素可以明显提高免疫器官指数(P<0.05)。对血清生化指标的测定结果表明,糖肽酮萜素组鸡的血清总胆固醇、甘油三酯和低密度脂蛋白胆固醇含量比抗生素对照组和空白对照组均有明显降低(P<0.05);而高密度脂蛋白胆固醇含量却反映出相反的趋势,试验组比对照组有了明显提高(P<0.05)。试验组的血氨浓度、尿酸含量显著低于空白对照组(P<0.05),与抗生素组差别不显著(P>0.05)。本研究结果证明:糖肽酮萜素完全可以替代抗生素类饲料添加剂。