强效艾美耳鸡球虫苗Ⅰ型的田间试验

本文报道了强效艾美耳牌鸡球虫苗I型对AA肉用仔鸡的田间免疫效果，马杜霉素或地克珠利作为对照药物，另一组以不用任何制球虫药物作为对照，实验显示，与马杜霉素相比，使用强效艾美耳牌鸡球虫苗I型后，AA肉用仔鸡在增重，饲料效率和成活率方面的优势，与地克球利相比，使用强效艾美耳牌鸡球虫苗I型后，AA肉用仔鸡在增重和饲料效率方面，效果相当，但成活率高1％，与不用抗球虫药物组相比，使用强效艾美耳牌鸡球虫苗I型后，鸡群在增重，饲料效率，成活率方面，均有显著优势。     

秦皇岛地区鸡球虫抗药性研究

应用艾维茵肉仔鸡，以最适抗球虫活性百分率（POAA）、病变记分减少率（RLS）和相对卵囊产量（ROP）为判定指标，检测了采自河北省秦皇岛地区的6种艾美耳球虫对8种常用抗球虫药物的敏感性。结果表明：6种混合艾美耳球虫对马杜霉素和盐霉素具有轻度抗药性；对拉沙洛菌素和氨丙淋具有中度抗药性；对球痢灵、克球多和常山酮具有重度抗药性；对地克珠利无抗药性。     

复方抗球虫药临床效果观察

复方抗球虫药(妥曲珠利-马杜霉素铵溶液)是一种西药复方制剂,主要用于防治鸡球虫病。本试验主要研究复方抗球虫药临床抗球虫效果并进行推广。在临床上治疗经柔嫩艾美耳球虫南通株人工接种的AA肉仔鸡,结果表明,妥曲珠利-马杜霉素铵抗球虫指数大于180,属于高效抗球虫药物。在各剂量组鸡的粪便和盲肠中均没有检查到球虫卵囊,说明没有耐药的突变虫株。对鸡球虫病的防治效果显著优于马杜霉素铵预混剂和妥曲珠利溶液,对鸡球虫具有高效的防治作用。     

安徽3个地区柔嫩艾美耳球虫对6种药物的抗药性

目的检测三株柔嫩艾美耳球虫对六种药物的耐药性,为防治球虫病制定临床用药方案提供依据。方法鸡体实验法检测巢湖、六安、肥东三株柔嫩艾美耳球虫对马杜拉霉素、盐霉素、莫能菌素、磺胺喹嗯啉钠、地克珠利、妥曲珠利的耐药性,以抗球虫指数（ACI）、病变记分减少率（RLS）、相对盲肠卵囊产量（ROP）和最适抗球虫活性百分率（POAA）四项指标综合判定。结果巢湖株对地克珠利,盐霉素与莫能菌素轻度耐药,对马杜拉霉素中度耐药,对托曲株利和磺胺喹嗯啉钠重度耐药,六安株对地克株利与托曲株利重度耐药,对磺胺喹嗯啉钠中度耐药,对盐霉素轻度耐药,对马杜霉素敏感,肥东株对磺胺喹嗯啉钠完全耐药,对莫能菌素重度耐药,对马杜霉素与盐霉素轻度耐药,对地克珠利与托曲珠利中度耐药。结论3个地区的柔嫩艾美耳球虫对供试药物已产生不同程度的耐药性。     

强效艾美耳牌鸡球虫疫苗免疫效果的研究

本实验研究了强效艾美耳牌鸡球虫疫苗免疫预防鸡球虫病的效果。实验结果表明：强效艾美耳牌鸡球虫疫苗是安全有效的，基保滴服免疫的效果优于拌料免疫，滴服免疫不仅对攻毒后鸡有100％的保护效果，而且能有效地控制球虫病的发生，对小鸡的生长也有明显的保护作用。与常用抗球虫药氯苯胍相比，强效艾美耳牌鸡球虫疫苗预防鸡球虫病的效果优于氯苯胍，其对小鸡增重率、料肉比显示的效果也优于氯苯胍。     

地克珠利抗柔嫩艾美耳球虫凤阳地理株的效果观察

将 60只 1日龄蛋公鸡于无球虫条件下饲养至 30日龄时随机分为 5组 (Ⅰ、Ⅱ、Ⅲ、Ⅳ、Ⅴ组 )。Ⅰ组用地克珠利饮水 (每千克水 1mg) ;Ⅱ组地克珠利混饲 (每千克饲料 2mg) ;Ⅲ组为药物对照组 (每千克饲料克球粉 5mg) ;Ⅳ组为感染不给药 ;Ⅴ组为不感染不给药组。于给药当天 ,除Ⅴ组外 ,其他组鸡每只接种 1× 1 0 5个柔嫩艾美耳球虫凤阳地理株孢子化卵囊。根据各组鸡的存活率 ,相对增重率 ,病变记分 ,血便记分和抗球虫指数来观察药物疗效。试验结果表明 ,地克珠利能有效的控制凤阳地理株柔嫩艾美耳球虫。     

球安对人工感染球虫的岭南黄鸡保护效能试验

选择柔嫩艾美耳球虫、巨型艾美耳球虫和堆型艾美耳球虫人工混合感染岭南黄鸡,采用笼养和平养的方法,比较球安(Avatec)与甲基盐霉素、盐霉素、马杜霉素和球虫康对鸡球虫感染的保护效能.笼养试验结果显示,球安按110 mg/kg添加到饲料中,对3种球虫超高剂量(15万个孢子化卵囊)的混合感染具有很强的抑杀作用,其抗球虫指数和饲料报酬分别为181.5和1.77.平养试验显示,在球虫持续感染的情况下,从增重方面看,与阳性对照相比,球安组、甲基盐霉素和球虫康组在20、30、40和50日龄段体重始终差异极显著.除了盐霉素和马杜霉素以外,各试验组屠宰率与阳性对照相比差异不显著;与阴性对照相比差异不显著.在胸肌率方面,无论是与阴性对照还是与阳性对照相比,均为差异不显著.     

家禽使用马杜霉素中毒的防治

马杜霉素是继莫能菌素、盐霉素、拉沙洛菌素等之后的一种新型聚醚类离子载体抗生素，由放线菌发酵而产生。马杜霉素具有很广的抗球虫谱，对柔嫩艾美耳、堆型艾美耳、布氏艾美耳、变位艾美耳及毒害艾美耳球虫都有很好的效果。     

海南霉素钠预混剂对鸡毒害艾美耳球虫的效力试验

为评价海南霉素钠预混剂对鸡毒害艾美耳球虫的疗效,采用人工感染的方式,选用180只鸡健康雏鸡,随机分为5组,每组30只。除不感染不给药组外,每组鸡均经嗉囊感染毒害艾美耳球虫孢子化卵囊2×10^4个。受试药物与对照药物均经混饲给药,海南霉素钠浓度为7.5mg/kg,莫能菌素浓度为100mg/kg,地克珠利浓度为1mg/kg,给药持续时间为10d,期间动物均自由采食。结果显示:海南霉素钠预混剂在防治爆发性球虫病时有良好效果,综合其对鸡人工感染毒害艾美耳球虫的临床症状(血便)、病变损害和卵囊的控制及增重等影响,海南霉素钠预混剂按推荐剂量7.5mg/kg连续使用10d,对鸡毒害艾美耳球虫有较好的疗效。     

5株柔嫩艾美耳球虫对4种抗球虫药的抗药性

选择260只19日龄雏鸡，随机分成26组，每组10只，研究柔嫩艾美耳球虫(E．tenella)南京株、凤阳株、扬州株、宣城株和蒙城株对地克珠利(Diclazuril)、马杜霉素(Maduramicin)、氯羟吡啶(C1opido1)、氯苯胍(Robenidine)的抗药性。每株球虫均设4个感染用药组、1个感染不用药组，另外设1个不感染不用药组。以POAA、RLS、ROP、ACI作为指标，判定5株球虫对4种药物的抗药性。结果表明凤阳株、扬州株和蒙城株分别仅对马杜霉素、氯苯胍、地克珠利敏感，南京株和宣城株对该4种药物均已产生不同程度的抗药性。提示目前在凤阳、扬州和蒙城地区可分别合理地使用马杜霉素、氯苯胍和地克珠利，对其它药物须减少或暂停使用。     

强效艾美耳牌鸡球虫苗的免疫效果

在实验条件下,研究了强效艾美耳牌鸡球虫苗对平养鸡群的免疫效果。实验１比较了免疫鸡群和对照鸡群在接种后１、２、３、４、５、６周的肠道病变分,结果表明免疫鸡群较自然感染建立免疫的对照鸡群的免疫整齐度高,判断依据是免疫后２周盲肠细小、内容物亦少的眼观指标。实验２比较了免疫鸡群、不免疫不用药鸡群、不免疫用药鸡群在攻虫后的三处肠道病变,结果表明免疫鸡群对大剂量卵囊攻击有很强的抵抗力。实验３比较了免疫鸡群、不     

The efficacy and economic benefits of Supercox, a live anticoccidial vaccine in a commercial trial in broiler chickens in China

The efficacy and economic benefits of Supercox, a live anticoccidial vaccine were examined and compared with an anticoccidial drug in a trial in broiler chickens under modern commercial conditions in China. In total, 40,660 chickens were used in the present study, half of which were vaccinated with the Supercox vaccine comprising a precocious line of Eimeria tenella and non-attenuated lines of Eimeria maxima and Eimeria acervulina, and the other half were medicated with Diclazuril delivered as feed additive at the dosage of 1mg/kg of feed. The vaccine was administered orally to 7-day-old chickens. No clinical diseases were diagnosed in any of the vaccinated birds. However, clinical coccidiosis occurred in a large proportion of medicated control birds and these chickens had to be treated with anticoccidial drugs (Diclazuril and Toltrazuril). Comparison of production performance between vaccinated birds and medicated control birds revealed that the vaccine Supercox performed better than anticoccidial drugs in terms of mortalities, costs and overall economic benefits (profits). These findings demonstrated that the use of the Supercox vaccine could control clinical coccidiosis in broilers and achieve production performance superior to that using anticoccidial drugs, particularly where drug resistance might result in failure to control clinical diseases.     

Comparison between a live, attenuated anticoccidial vaccine and an anticoccidial ionophore, on performance of broilers raised with or without a growth promoter, in an initially Eimeria-free environment.

An experiment was carried out to study the effects of vaccination with Paracox, a live, attenuated vaccine against avian coccidiosis, on broilers isolated from extraneous Eimeria parasites. The study involved 3200 broiler chickens raised in floor pens similar to commercial conditions, but in an initially Eimeria-free environment. Forty percent of the chickens were vaccinated at 3 days of age and given either a basal unmedicated feed or a feed supplemented with the feed antibiotic virginiamycin. Unvaccinated birds were given either the basal feed or feed supplemented either with virginiamycin or the anticoccidial ionophore narasin. At slaughter at 36 days of age vaccinated birds had a lower live weight than non-vaccinated birds. The difference was 4.6% in unmedicated, and 6.0% in virginiamycin medicated chickens. Feed conversion ratio at slaughter was 2.5% higher for unmedicated vaccinated birds, and 1.3% higher for virginiamycin medicated vaccinated birds, compared to respective non-vaccinated groups. There was no significant difference in overall performance of unvaccinated birds given narasin as compared to virginiamycin. At 10 days post vaccination vaccinated birds had a higher number of Clostridium perfringens in the caeca, but there was no difference thereafter. Throughout the experiment, caecal clostridial counts were considerably higher in vaccinated unmedicated birds than in unvaccinated birds given narasin. The number of oocysts shed in the vaccinated groups was very low, but during a subsequent challenge with E. maxima and E. tenella the birds' immunity was found to be satisfactory.     

Higher incidence of Eimeria spp. field isolates sensitive for diclazuril and monensin associated with the use of live coccidiosis vaccination with paracox-5 in broiler farms

Twenty European Eimeria spp. field isolates were subjected to an anticoccidial sensitivity test (AST). The anticoccidial drugs tested were diclazuril (Clinacox) and monensin (Elancoban). The assay was performed in a battery cage trial. Infected medicated birds were compared with an unmedicated control group. Coccidial lesion scores and oocyst shedding were used as parameters. The results of the AST show that resistance is common amongst coccidiosis field isolates, especially Eimeria acervulina (68% and 53% resistance for diclazuril and monensin, respectively). Resistance is less frequent amongst Eimeria maxima (38% and 50% resistance for diclazuril and monensin, respectively) and Eimeria tenella isolates (23% and 38% resistance for diclazuril and monensin, respectively). A highly significant influence of the coccidiosis prevention program (live coccidiosis vaccination with Paracox-5 vs. anticoccidial drugs in feed) on the sensitivity patterns of Eimeria spp. field isolates for both diclazuril (P= 0.000) and monensin (P= 0.001) was found. Further, when looking at the single species and each anticoccidial drug level, significantly more sensitivity of E. acervulina for monensin (P= 0.018), E. maxima for diclazuril (P = 0.009), and E. tenella for diclazuril (P = 0.007) was found in isolates originating from vaccinated flocks. Moreover, for E. acervulina and diclazuril, E. maxima and monensin, and E. tenella and monensin a trend toward higher sensitivity of isolates for these products was found when live coccidiosis vaccination was applied. The present study shows that sensitivity for the anticoccidial drugs diclazuril and monensin is more frequent in Eimeria spp. field isolates originating from broiler farms where a coccidiosis vaccination policy is followed.     

Effects of a herbal complex against Eimeria tenella infection in chickens

A liquid and a powder made from a herbal complex consisting of Uncariae Ramulus cum Uncis, Agrimoniae Herba, Sanguisorbae Radix, Eclipta Prostrate Herba, Pulsatillae Radix, Sophorae Flavescentis Radix, Rehmanniae Radix and Glycyrrhizae Radix were studied for their anticoccidial activities in chickens. Chickens were administered with herbal liquid, powder, diclazuril or without medication during the study and challenged with oocysts of Eimeria tenella. Results indicated that the birds medicated showed less bloody faeces than those without medication. The intestinal lesion was mild in the chicks medicated with herbal liquid without significantly different lesion score when compared with uninfected chicks. The birds with medication had significantly higher body weight gains than birds without medication. Therefore, the herbal complex used in this study was effective against E. tenella infection in chickens.     

Responses of chickens vaccinated with a live attenuated multi-valent ionophore-tolerant Eimeria vaccine

Coccidiosis, caused by Eimeria species, is a serious economic disease of chickens (Gallus gallus) and the search for vaccines to control the disease is intensifying especially with the increasing threat of drug resistance. A live attenuated multi-valent ionophore-tolerant Eimeria vaccine has been developed that contains three ionophore-resistant Eimeria species, E. tenella, E. maxima and E. acervulina. The attenuated lines were derived from virulent field strains resistant to monensin ionophore by selection for early development in chicks. The vaccine was administered by gavage and through drinking water to broiler chickens, Chinese Yellow strain, reared in wire cages. Vaccinated medicated birds performed better than vaccinated unmedicated and medicated unvaccinated groups. The final mean weights of vaccinated medicated birds were significantly higher (P<0.05), and a better vaccine protection index, using both vaccinating methods, was achieved. Results indicated that concomitant use of ionophores and vaccines could be a useful adjunct to planned immunization in the control of coccidiosis.     

Use of Yucca schidigera Extract in Broiler Diets and Its Effects on Performance Results Obtained with Different Coccidiosis Control Methods

A trial was conducted to assess the effects of the dietary supplement Yucca schidigera extract on the performance of broilers subjected to different coccidiosis control methods. Six hundred male broiler chicks were randomly allocated to 1 of 5 treatments with 4 replicates each. The treatments were as follows: T1, vaccinated against coccidiosis; T2, nonvaccinated, a dietary coccidiostat; T3, vaccinated against coccidiosis, diet supplemented with Y. schidigera extract (0.01%); T4, coccidiostat plus Y. schidigera extract added to feed (0.01%); and T5, nonvaccinated, nonsupplemented control. The parameters analyzed were bird performance and morphology of the intestinal mucosal surface. The intestinal villi were higher at 6 d of age in broilers treated with coccidiostats or vaccinated against coccidiosis and supplemented with Y. schidigera extract compared with groups receiving the vaccine only or no treatment. Addition of the Y. schidigera extract to the diet of vaccinated birds improved average daily gain and feed conversion rate at 42 d of age compared with the other treatments, suggesting there might be a beneficial, synergistic effect between the coccidiosis vaccine and the Y. schidigera extract.     

Coarse-spray immunization of one-day-old broilers against enteric reovirus infections.

Coarse-spray (CS) administration of a commercial S1133 reovirus vaccine was evaluated in 1-day-old specific-pathogen-free broilers for prevention of clinical infection induced by intratracheal challenge with two enteric reovirus isolates. In Expt. 1, chickens were challenged at 4 days of age with either the 2408 or CO8 isolate. In Expt. 2, chickens were challenged at 7 days of age with either isolate. In Expt. 3, chickens were challenged at 3, 5, or 7 days of age with the 2408 isolate. In Expt. 1, vaccinated birds showed significant protection against challenge with either isolate at 4 days of age as measured by morbidity, mortality, gross lesions, and body weight. In Expt. 2, vaccinated birds showed greater protection against challenge at 7 days of age. In Expt. 3, resistance in vaccinated birds increased with time between vaccination and challenge. Vaccinated birds challenged at 3 days of age showed no significant protection, whereas vaccinated birds challenged at 5 or 7 days of age had increased resistance. This vaccine did not induce a drop in weight gain, morbidity, mortality, or microscopic lesions in the tendons.     

Field trials of a food-based vaccine to protect village chickens against Newcastle disease

The food pellet vaccine has been shown to be effective in trials conducted under laboratory and simulated field conditions. The village chickens vaccinated with the food pellet vaccine during the field trial were protected against virulent Newcastle disease virus. The efficacy of the food pellet vaccine in the field was evaluated by challenge trial in which 60 per cent protection was obtained, or by monitoring the incidence of Newcastle disease in vaccinated and unvaccinated birds. There was no report of Newcastle disease outbreaks in the vaccinated birds during the two-year period of the field trial. The ease in administering the food pellet vaccine makes it readily accepted by the farmers.     

Safety of the attenuated anticoccidial vaccine ‘Paracox’ in broiler chickens isolated from extraneous coccidial infection

A trial was carried out in 1-day-old broiler chicks raised for 54 days in floorpens under simulated commercial conditions, but isolated from all extraneous virulent coccidial infections, to demonstrate the safety of Paracox attenuated vaccine administered at the recommended dose when chicks were 7 days old. The vaccine did not adversely affect the water consumption, faecal moisture or litter condition of the broilers. Recycling of the attenuated coccidia occurred in vaccinated birds, oocysts being present in the litter between 5 and 33 days after vaccination; a single peak of oocysts was detectable 5 or 12 days after vaccination. Unvaccinated medicated control birds did not produce oocysts, indicating freedom from both between-pen contamination by the vaccine and invasion of the chicken-house by extraneous coccidial infection. A small proportion (4%) of vaccinated birds had mild coccidial lesions when sampled at 26, 33 or 40 days after vaccination. Despite this, the vaccinated birds performed better than control (unvaccinated, nicarbazin-treated) birds and there was no post-vaccinal check in their weight gain. Their mean finishing weight was 10.4% greater, their food conversion ratio 7.2% lower and their mortality 44.4% lower than the unvaccinated control birds, reflecting the safety of Paracox vaccine.Abbreviation FCR food conversion ratio