三种鸡抗球虫药的效力比较试验

鸡球虫病是养禽业中常见的一种疾病,它对养鸡生产的危害十分严重,分布很广。在我国虽然已使用抗球虫药物的种类很多,但由于球虫耐药性的普遍存在,抗球虫效果不是很理想。本试验通过挑选健康雏鸡随机分组,在人工感染鸡柔嫩艾美耳球虫条件下,评估三种抗球虫药物（磺胺氯吡嗪钠、马杜拉霉素、盐酸氯丙嗪）的抗球虫效果,并对三种抗球虫药物进行比较,以抗球虫指数（ACI）作为药物治疗效果的综合评定指标,为规模化养鸡场提供实验依据,以适应生产实际需要。     

三种鸡抗球虫药物效力的比较研究

挑选健康和体况相近的104只15～25日龄雏鸡,随机分组,在人工感染鸡柔嫩艾美耳球虫条件下,评估3种抗球虫药物——磺胺氯吡嗪类、马杜拉霉素、盐酸氯丙嗪的抗球虫效果,并对3种抗球虫药物进行比较,以抗球虫指数（ACI）作为药物治疗效果的综合评定指标。结果表明,各药物组的ACI分别为磺胺氯吡嗪类184.35,马杜拉霉素142.06,盐酸氯丙嗪165.10,显示磺胺氯吡嗪类药物抗球虫效果最好。     

三种鸡用不同抗球虫药物的药效对比试验

选择健康和体况相近的15～25日龄雏鸡104羽,随机分为5组,在人工感染鸡柔嫩艾美耳球虫条件下,评估三种不同抗球虫药物,磺胺氯吡嗪类、马杜拉霉素、盐酸氯丙嗪的抗球虫效果,以抗球虫指数（ACI）作为药效的综合评定指标。结果显示,各药物组的ACI分别为磺胺氯吡嗪类184.35,马杜拉霉素142.06,盐酸氯丙嗪165.10,显示磺胺氯吡嗪类抗球虫效果最好,盐酸氯丙嗪次之。     

复方抗球虫药对鸡盲肠球虫病的治疗效果比较

应用96只罗曼雏鸡,检测了3种浓度禽球清、2种浓度杀球灵药物对盲肠球虫的抗球虫效力。试验分8组,设6个药物组,1个感染不用药组,1个不感染不用药组,每组12只鸡。除第8组,每只鸡感染7×104万已孢子化柔嫩艾美耳球虫卵囊。根据相对增重率、存活率、病变值和卵囊值四个参数计算抗球虫指数(ACI)。8组试验结果的ACI分别为122、132、132、144、182、132、129、200。依据抗球虫效力进行判定,只有杀球灵正常量的组效果为优,其余的组药物效果均为差。     

癸氧喹酯抗柔嫩艾美耳球虫洛阳分离株的效果试验

以抗球虫指数(Anticoccidial Index,ACI)、料肉比及增重为指标,研究了癸氧喹酯抗鸡柔嫩艾美耳球虫洛阳分离株的效果.结果表明,根据54.4 mg/kg、27.2 mg/kg、13.6 mg/kg体重的剂量按饲料比拌料给药,抗球虫指数(ACI)分别达到183.57、145.53和127.80,与感染不给药组相比,料肉比分别降低30.04％、10.60％和3.18％,高剂量组增重与不感染对照组没有显著差异.癸氧喹酯以54.4 mg/kg体重的浓度拌料可以预防洛阳地区鸡球虫病感染,试验结果为临床上有效利用癸氧喹酯控制鸡球虫病提供了重要依据.     

五种抗球虫药物对鸡柔嫩艾美耳球虫病的疗效观察

210只14日龄817肉杂鸡公雏随机均分为7组,每组30只,除白对照组外,每只鸡接种2×105个柔嫩艾美耳球虫孢子化卵囊,同时选择百球杀二代、球痢速治、海南霉素、球虫宝,海南地克珠利5种常用抗球虫药,通过饮水给药的方式,观察其疗效,试验期为10 d。结果表明,百球杀二代的抗球虫指数(ACI)为197.7,属高效抗球虫药。抑制卵囊繁殖和减轻肠道病变效果以海南霉素组为显著,整个试验期内的增重分别比红对照组、白对照组、其他药物组均高。球痢速治、海南霉素、球虫宝的抗球虫指数(ACI)分别为184.6、174.9、165.2,均为中效抗球虫药。地克珠利的抗球虫指数(ACI)为142.9,判为低效抗球虫药。红对照组的法氏囊指数与其他各组之间差异不显著(P0.05),脾脏指数与白对照组差异不显著(P0.05),与百球杀二代组,汇鑫球痢速治组和海南霉素组差异极显著(P0.01),与球虫宝组和海南地克珠利组差异显著(P0.05)。     

青蒿散抗鸡球虫药效研究

为探讨青蒿散对鸡柔嫩艾美耳球虫（E.tenella）的防治效果,本试验选取90只健康黄羽肉鸡,分为6组,除空白对照组外,其余各组（感染对照组、药物对照组及青蒿散低、中、高剂量组）试验鸡均经口感染6×10⁴个柔嫩艾美耳球虫孢子化卵囊,各试验组在接种前一天开始用药至试验结束。记录各组试验鸡的眼观病变、组织病理学检查、相对增重率、盲肠病变记分、血便记分、每克粪便中的卵囊数（OPG）、卵囊值及抗球虫指数（ACI）指标,评价青蒿散不同给药浓度的抗球虫效果。结果显示,空白对照组、感染对照组、药物对照组及青蒿散低、中、高剂量组的抗球虫指数分别为200.00、72.23、157.19、82.89、125.32和137.06,与感染对照组相比,药物对照组和青蒿散各剂量组的眼观病变、组织病理学检查均有所缓解,青蒿散能减轻病鸡盲肠的肿胀和出血等症状,且病鸡精神状态较感染对照组好;与感染对照组相比,各给药组的平均增重均有所升高,盲肠病变、卵囊值及血便情况减少。综上所述,青蒿散能缓解柔嫩艾美耳球虫侵染鸡盲肠所致的病理症状和组织病变,减少粪便中卵囊的排出数量,有一定的抗球虫效果,且给药浓度越高抗球虫效果越好,具有剂量依赖性。     

抗鸡柔嫩艾美耳球虫中药复方的筛选(初报)

采用人工感染发病方法，对由常山，柴胡，青蒿、白头翁，地榆，黄芪等十多味中草药按照不同的组成和配比组成的12个中药复方的抗鸡柔嫩艾美耳球虫的效果进行了试验观察，结果方6和12效果最佳，抗球虫指数分别达131．13和132．15，较感染不给药组分别提高了138．85％和140．71％，存活率也均达100％，相对增重率分别为71．13％和73．15％，较感染不给药组分别提高了17．23和19．25个百分点。     

Studies on the mode of action of anticoccidial drugs in the chicken and chicken embryo

Delayed treatment has been used to investigate the activity of anticoccidials against the Houghton strain and an embryo-adapted strain of E. tenella. The results show that in chicken embryos the effect of the quinolones and clopidol depends upon the concentration of drug employed. The earlier stages in the life cycle appear to be intrinsically more vulnerable to the action of these drugs. In the chicken, the activity of amprolium was restricted to early stages in the life cycle, but in the chicken embryo, where development is restricted to the thin chorioallantoic membrane, all stages present up to 72 h after inoculation were equally affected. Absorption and distribution may, therefore, limit the action of amprolium in the chicken. Robenidine and sulphaquinoxaline were equally active up to 72 h post inoculation in chickens and chicken embryos, suggesting that absorption and distribution do not limit the activity of these drugs.     

Sensitivity of field isolates of Eimeria tenella to anticoccidial drugs in the chicken

Thirty isolates of Eimeria tenella obtained from broiler and breeder farms were examined for their sensitivity to anticoccidial drugs. All were sensitive to robenidine, 28 were sensitive to methyl benzoquate, 25 to clopidol and 21 to nicarbazin. Most isolates were resistant or partly resistant to amprolium and dinitolmide.     

Response of 21 Canadian field isolates of chicken coccidia to commercial anticoccidial drugs

Coccidia were isolated from 30 broiler farms in major poultry-producing provinces of Canada; 21 mixed-species isolates were tested for sensitivity to anticoccidial drugs. Eimeria acervulina was identified in 20 samples, E. maxima in 15, and E. tenella in 10 of the mixed-species isolates. On the basis of weight gain after infection, 3 isolates were judged sensitive to amprolium, 5 to monensin, 9 to salinomycin, 14 to lasalocid, 19 to halofuginone, and 20 to nicarbazin. Similar trends in sensitivity/tolerance were identified from the percent reduction of intestinal lesion scores of medicated birds compared with scores of unmedicated, infected controls. These results were consistent with the previous pattern of use of anticoccidial drugs in commercial poultry in Canada.     

优化抗球虫病疫苗在肉鸡的效力

抗球虫病疫苗的成功应用,不仅仅是简单地将疫苗用于雏鸡就了事。为了获得保护性免疫力从而产生最佳的经济效益,必须对免疫接种的方法加以精心控制,必须对卵囊的摄入量和产生的免疫力进行监测,开发出的防制措施还必须能够确保生长中肉鸡的一般健康和福利需求以及肉鸡所处环境的质量。     

Fetotoxicity of some anticoccidial drugs in chickens

Fetotoxic effects induced by three anticoccidial drugs: robenidine, salinomycin and arprinocid were elucidated in the chicken. Different doses of these drugs were inoculated in groups of embryonated chicken eggs by the yolk sac route. After inoculation, candling of the eggs was performed daily and embryonic or fetal mortalities were recorded. At 19 days old, alive fetuses were collected, weighed, measured and examined morphologically for abnormalities. A group of eggs was kept non-inoculated as a control and another was inoculated with the solvent of the tested drugs. Inoculation of 0.09-9.75 mg robenidine/egg, 0.06-6.75 mg salinomycin/egg or 0.08-8.25 mg arprinocid/egg into the yolk sac of 7 days old embryos caused a dose-dependent fetal death. Arprinocid was the most lethal to chicken fetuses, followed by salinomycin while robenidine was the least. Dead fetuses were usually haemorrhagic, dwarfish and friable. Surviving fetuses showed a dose-dependent reduction in body weight and length, insignificant decrease in leg and wing lengths as well as some developmental abnormalities.     

Differences between the anticoccidial potencies of monensin in maize-based or wheat-based chicken diets

Experiments were carried out to investigate why the anticoccidial ionophore monensin is more potent against the coccidiumEimeria tenella in chickens fed on a maize-based diet (as in the USA) than in chickens fed on a wheat-based diet (as in the UK). The explanation seems to be that the pathogenicity ofE. tenella is lower in maize-fed chickens than in wheat-fed chickens, whether monensin is present in the diet or not. Possible reasons for this are suggested. The better survival of maize-fed birds may be partly due to protective effects of the higher concentrations of vitamins A and E derived from their diet. Furthermore, the higher concentrations of niacin and riboflavin in wheat than in maize may enhance coccidial pathogenicity. These opposing factors might combine to cause equivalent infection levels to produce more severe coccidiosis in chickens fed on a wheat-based diet than on a maize-based diet.     

World Association for the Advancement of Veterinary Parasitology (WAAVP) guidelines for evaluating the efficacy of anticoccidial drugs in chickens and turkeys

These guidelines have been written to aid in the design, implementation and interpretation of studies for the assessment of drug efficacy against Eimeria species in chickens and turkeys. The information provided deals with many aspects of how to conduct controlled studies in battery cages (dose determination), floor pens (dose confirmation), and commercial facilities (field effectiveness studies), the selection of birds, housing, feeding, preparation of medicated rations, record keeping, diagnostic techniques, and methods for the preparation, maintenance and use of parasites. These guidelines are also intended to assist investigators in conducting specific studies, provide specific information for registration authorities involved in the decision-making process, assist in the approval and registration of new anticoccidial drugs, and facilitate the world-wide adoption of standard procedures.