Coccidiosis control with toltrazuril in conjunction with anticoccidial medicated or nonmedicated feed

A 42-day broiler floor pen study was conducted comparing the anticoccidial efficacy of toltrazuril (Baycox) as a stand alone treatment and as an additional treatment to in-feed anticoccidial programs. Toltrazuril was administered on days 18 and 19 in the drinking water at 7 mg/kg of body weight. The treatments were 125 ppm nicarbazin (days 0-14) to 66 ppm salinomycin (SAL) (days 15-35) with and without toltrazuril, SAL (days 0-35) with and without toltrazuril, nonmedicated (NM) to SAL with toltrazuril, and NM with and without toltrazuril. The controls were NM noninfected and infected. The treatments were replicated in five blocks of eight pens each in a randomized complete block design. All withdrawal feed was nonmedicated. On day 14, birds, except noninfected, were exposed to coccidial oocysts (Eimeria acervulina, Eimeria maxima, and Eimeria tenella) seeded litter. On days 21, 28, 35, and 42, birds and feed were weighed, four birds per pen were coccidial lesion scored, and litter oocyst counts were performed. The coccidial infection in the NM infected treatment caused a significant (P < 0.05) coccidiosis infection. Coccidiosis was moderately controlled in the anticoccidial treatment birds without toltrazuril. Performance in the NM with toltrazuril was equal to or better (P < 0.05) than the anticoccidial programs without toltrazuril. Toltrazuril was equal to the noninfected birds in performance. Toltrazuril most completely eliminated all coccidial lesions and dramatically reduced oocyst shedding. The performance data, lesion scores, and oocyst counts showed that a 2-day treatment with toltrazuril successfully controlled the coccidiosis with no relapse of infection. Toltrazuril can thus be used for supplemental control with in-feed anticoccidials or as a primary anticoccidial with nonmedicated feed.     

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.     

Use of toltrazuril in pullet breeding flocks raised on floors with anticoccidial-free feed

In 28 replacement pullet flocks with flock size of 4,000 to 25,000 birds Toltrazuril (experimental preparation, 2.5% solution, approx. 7 mg/kg body weight) was administered for a period of two days in the drinking water for metaphylactic purpose and therapeutic use, respectively. All flocks were reared without anticoccidial feed additives. Exposition to Eimeria spp. was recorded by examination of faecal samples and intestinal scrapings. Clinical flock control was achieved by vets at eight to ten day intervals. Toltrazuril was characterized by short application period, rapid mode of action, significant reduction of oocyst shedding, good compatibility and acceptance thus proving superior to conventional chemotherapy of coccidiosis. The results suggest that, even without administration of anticoccidial feed additives. Toltrazuril is an effective agent for therapeutic use in acute coccidiosis. Under insufficient management and rearing conditions repeated metaphylactic application has to be considered.     

妥曲珠利治疗鸡球虫病用药方案的优化

目前,妥曲珠利的用药时间和用药途径及其治疗效果存在争议。为了确定妥曲珠利对鸡球虫病的最佳用药时间和途径,本试验以自由饮水和灌服两种途径分别在感染球虫孢子化卵囊后24、48、72 h连续用药2 d,通过抗球虫指数（anticoccidialindex,ACI）、排卵囊减少率和死亡率等指标分析妥曲珠利饮水剂合理用药方案。结果表明,感染后24 h用药妥曲珠利可有效控制鸡柔嫩艾美耳球虫病,48 h后治疗效果不佳;嗉囊灌服的治疗效果优于自由饮水。本试验结果为生产中有效利用妥曲珠利控制鸡球虫病提供了重要依据。     

Anticoccidial efficacy of diclazuril against recent field isolates of Eimeria from commercial poultry farms

The anticoccidial efficacy of diclazuril, a novel anticoccidial agent, was titrated in laboratory experiments using recent field isolates of Eimeria. Fifty tests were conducted with six individual species isolates, and seven tests were done with a mixture of the six species. Results were based on intestinal lesion scores at necropsy, droppings scores, and weight gain. Diclazuril at 0.5 ppm was almost completely effective against E. tenella, E. acervulina, and E. mitis. Prevention of E. brunetti was better at 1.0 ppm than at 0.5 ppm. In birds infected with E. mitis. Prevention of E. brunetti was better at 1.0 ppm than at 0.5 ppm. In birds infected with E. maxima, diclazuril at 0.5-1.5 ppm significantly reduced lesion scores and droppings scores and improved weight gain, although lesions were higher than with other species. Oocyst shedding by E. maxima was almost completely prevented by 0.5-1.5 ppm. Lesion scores and droppings scores caused by E. necatrix or mixed infections were greatly reduced by 0.5 ppm of diclazuril, but 1.0 ppm was necessary to obtain full protection of weight gain. Results suggest that 1.0 ppm of diclazuril best prevents coccidiosis caused by six species of coccidia in chickens.     

Anticoccidial efficacy of diclazuril in pheasants

Diclazuril, a new anticoccidial drug, was tested in young pheasants artificially infected with the three most common pathogenic species of Eimeria, E colchici, E duodenalis and E phasiani. In two replicate experiments each with 40 birds the mortalities in the infected controls were 50 and 25 per cent. Diclazuril was administered in the feed at dose levels of 1, 2 and 4 ppm from the day before the inoculation of coccidia until the end of the test on day 6 after infection. The 1 ppm dose failed to inhibit the development of the parasite completely, as was shown by a reduction of the weight gain of the birds and the output of a small number of oocysts. Diclazuril at 2 or 4 ppm adequately controlled the infection, with weight gains similar to those of the uninfected controls. At all dose levels, mortality, intestinal lesions and diarrhoea were prevented.     

几种药物对兔球虫病的疗效试验

选用40只45日龄左右、严重自然感染兔球虫的日本大耳白兔,随机分成5组,即兔球灵组(1500mg/kg)、地克珠利组(2mg/kg)、拉沙洛菌素组(150mg/kg)、氯苯胍组(300mg/kg)、不给药对照组,分别将药物按一定比例混匀在饲料中,制成颗粒料让兔自由采食,以比较其对兔球虫病的治疗效果.通过临床观察,分析每克粪便卵囊数的变化,记录增重,计算饲料转化率并对每组兔剖杀作剖解观察.结果表明:兔球灵、地克珠利和拉沙洛菌素对抑制兔球虫卵囊产生,减轻肠道病理损害,降低幼兔死亡率,保护兔只增重和提高饲料转化率的作用极显著优于氯苯胍(P＜0.01);氯苯胍抗球虫效果较差,与不给药对照组差异不显著(P＞0.05);但较长时间连续使用拉沙洛菌素对兔有较大的毒副作用.试验证明氯苯胍不宜单一长期使用,应选用新型高效抗球虫药或变换用药或联合用药.     

Chemoprophylaxis of coccidiosis in lambs with a single oral dose of toltrazuril

The prophylactic efficacy of a single oral dose of toltrazuril against coccidiosis (mixed Eimeria infections) in naturally infected lambs was evaluated in two experiments. Toltrazuril at 20 mg kg-1, given on Day 7 or Day 10 after turnout on pasture, proved to be highly efficacious in preventing clinical coccidiosis under Norwegian conditions. Toltrazuril reduced the oocyst output to very low levels, prevented the development of diarrhoea and improved weight gain during the first 4-5 weeks after treatment. Treatment on Day 7 was superior to treatment on Day 10 with respect to improving weight gain and preventing the development of soft faeces. Lambs treated with toltrazuril on Day 7 seemed to be as immune as untreated lambs to natural reinfections with coccidia later in the grazing season. In one of the experiments, natural infections with the nematode Nematodirus battus produced a coccidiosis-like disease in some lambs simultaneously with the outbreak of coccidiosis.     

Isolation of five species ofeimeria from chickens in Bangladesh

Five species of Eimeria, namely E. acervulina, E. tenella, E. maxima, E. brunetti and E. necatrix were identified in chickens in Bangladesh on the basis of lesions seen at post-mortem examinations of naturally infected birds, and on the dimensions of oocysts and the lesions seen in chicks experimentally infected with single oocyst derived strains. The use of filter top, polycarbonate cages permitted the isolation of strains without sophisticated animal isolators and is appropriate for use in laboratories throughout the developing world. Responses to a questionnaire sent to all known intensive poultry farms suggested that coccidiosis is a major disease. For control, producers rely mostly on management procedures and the tactical use of sulphonamides; in-feed chemoprophylaxis is not widely used. These control measures are unsatisfactory and recent coccidiosis outbreaks were reported from seven of 16 farms. There was evidence of a seasonal incidence in clinical coccidiosis.     

柔嫩艾美耳球虫对地克珠利和百球清的交叉耐药性检验

分别采用地克珠利和百球清饮水剂对3株来源和特性不同的柔嫩艾美耳球虫株进行了交叉耐药性检验。结果表明，从未接触过百球清的敏感株和由敏感株诱导而成的地克珠利耐药株均表现出对百球清高度敏感；而曾使用过二种药物的野外分离虫株，则表现出对两种药物高度耐药。由此可见，两种药物并不存在必然的交叉耐药性。     

妥曲珠利对人工感染鸡柔嫩艾美尔球虫病的临床治疗试验

为比较、测定国内厂家生产的妥曲珠利可溶性对鸡球虫病的治疗效果,试验设计三个剂量组,并以德国拜耳公司生产的百球清作为药物对照,进行饮水治疗人工感染艾美尔球虫病,一日2次,连用3 d。结果表明,受试药物的高(0.75 g/L)、中(0.5 g/L)剂量组,能显著降低球虫病感染引起的死亡率、血便、盲肠病变,并提高相对增重率(P0.05)。推荐国内厂家生产的妥曲珠利可溶性粉最佳临床治疗用法为:剂量0.5 g/L,连续饮水给药3 d。     

中药与化学药物对鸡球虫病的疗效对比试验

研究应用中药方剂对鸡球虫病进行了疗效试验,结果表明中药方剂具有明显的抗球虫和促进小鸡增重的效果,中药组与地克珠利组和氨丙啉组的抗球虫指数(ACI)分别为216.1,182.9和144.2,说明中药的抗球虫效果明显优于化学药物;两种化学药物中,地克珠利仍属高效抗球虫药,但氨丙啉的ACI仅有144.2,为低效抗球虫药,已不宜继续用于防治鸡球虫病。     

Efficacy of selected coccidiostats in sandhill cranes (Grus canadensis) following challenge.

The anticoccidial efficacy of amprolium, clazuril, and monensin were studied in sandhill cranes (Grus canadensis) infected with a mixture of Eimeria spp. oocysts. Five groups of four 1-day-old sandhill crane chicks were maintained on a crumbled ration containing no coccidiostat, amprolium at 2.2 ppm, clazuril at 1.1 ppm, clazuril at 5.5 ppm, or monensin at 99 ppm. After 2 wk on their respective feeding regimens, birds in each of the five groups were administered 25 x 10(3) pooled sporulated Eimeria spp. oocysts per os and observed for another 3 wk. A sixth group of four chicks served as nonmedicated, nonchallenged control during the study. Clinical signs and lesions consistent with disseminated visceral coccidiosis were observed in all challenged controls and birds fed amprolium and clazuril. Birds in these groups died 9-10 days after challenge. In contrast, only one monensin-medicated bird had clinical signs of disseminated visceral coccidiosis, and it died 13 days after challenge (DAC). This and an asymptomatic bird that were necropsied at study termination had less-severe gross and microscopic lesions of disseminated visceral coccidiosis. Two of three monensin-treated birds that survived challenge passed from 50 to 500 coccidial oocysts 11 to 18 DAC but were negative at study termination. Of the coccidiostats tested, monensin, at the dietary level of 99 ppm, was the only anticoccidial drug that provided protection against experimentally induced disseminated visceral coccidiosis in sandhill cranes.     

Direct effects of Moringa oleifera Lam (Moringaceae) acetone leaf extract on broiler chickens naturally infected with Eimeria species

Avian coccidiosis is one of the most important diseases of poultry and it is responsible for a large number of all broiler mortalities worldwide. The control of this disease relies mainly on the use of anticoccidial drugs. However, herbal preparations could be an alternative for the treatment against coccidiosis in chickens. The direct effects of Moringa oleifera acetone extracts on broiler chickens naturally infected with mixed Eimeria species was investigated to determine the relative efficacy of the extracts against coccidiosis in birds. The investigations were carried out in seven groups (ten chickens per group). The birds were given various doses (1.0, 2.0, 3.0, 4.0 and 5.0 g/kg body weight) of acetone extract of leaves of M. toltrazuril® (positive control) and untreated (negative control). The extract was evaluated for anticoccidial activity by means of inhibition of oocyst output in faeces, faecal score, weight gain and mortality. Haematological indices were evaluated by standard methods. The group treated with 1.0 g/ kg body weight Moringa oleifera extract produced the least inhibitory effect on oocyst shed in the faeces (96.4 %), while the groups treated with 2.0 g/kg, 3.0 g/kg, 4.0 g/kg and 5.0 g/kg body weight of the extract produced 97.4, 98.7, 99.1 and 99.8 %, respectively. Body weight gains of infected chickens treated with the extract significantly improved (p?<?0.05), and faecal scores were milder. Packed cell volume, haemoglobin concentration and red blood count of the treated birds were significantly (p?<?0.05) higher than those of the infected untreated group. Moringa oleifera leaves could find application in the treatment of avian coccidiosis in veterinary practice.     

Dietary enzyme and zinc bacitracin reduce colonisation of layer hens by the intestinal spirochaete Brachyspira intermedia

Brachyspira intermedia strain HB60 was used to experimentally infect 40 individually caged 22-week-old laying hens. Another 10 control birds were sham-inoculated with sterile broth. All chickens received an experimental layer diet based on wheat. The infected birds were randomly divided into four groups of 10, with the diet for each group containing either 50 ppm zinc bacitracin (ZnB), 100 ppm ZnB, 256 ppm of dietary enzyme (Avizyme), 1302), or no additive. Birds were kept for 6 weeks after infection, and faecal excretion of B. intermedia, faecal water content, egg numbers, egg weights and body weights were recorded weekly. Control birds remained uninfected throughout the experiment. B. intermedia was isolated significantly less frequently from the groups of experimentally infected birds receiving ZnB at 50 ppm or enzyme than from those receiving 100 ppm ZnB or no treatment. Infected birds had a transient increase in faecal water content in the week following challenge, but no other significant production differences were detected amongst the five groups of birds in subsequent weeks. It was not established how the ZnB at 50 ppm and the dietary enzyme reduced the ability of the spirochaete to colonise, but it may have been by bringing about changes in the intestinal microflora and/or the intestinal microenvironment.     

Efficacy of Calcium Fosfomycin for the Treatment of Experimental Infections of Broiler Chickens with Escherichia Coli O78:K80

Two trials were made to assess the efficacy of including calcium fosfomycin in the drinking water or in the feed for four days to control the adverse effects of experimentally induced colibacillosis in broiler chickens. Trial 1 had five groups of 15 chicks each: one group of negative controls; an untreated infected control group and three groups treated with 50, 100 or 200 ppm of calcium fosfomycin in drinking water. Trial 2 had the same groups but the antibiotic was incorporated into the feed. The chickens were infected via their air sacs with 1.7 x 10⁸–3.6 x 10⁸ CFU/chick of Escherichia coli O78:K80. The morbidity and mortality, a score for the gross lesions, the relative weight of the liver and spleen, performance and re-isolation of the challenge bacteria were recorded. Calcium fosfomycin in the drinking water controlled the colibacillosis, particularly in the group treated with 200 ppm. However, no effect of the antibiotic was seen when calcium fosfomycin was incorporated into the feed, the mortality, score of lesions and re-isolation of E. coli from the organs in the three treated groups being similar to those for the infected unmedicated group. The amount of antibiotic ingested in trial 1 was three times more than in trial 2. These results suggest that calcium fosfomycin is best used in the drinking water for the treatment of colibacillosis.     

Ovine coccidiosis: effect of the antibiotic monensin against Eimeria ninakohlyakimovae and other naturally occurring coccidia of sheep

Sixteen female and 16 male lambs were used in 4 groups to determine the effect of monensin on naturally occurring and experimentally induced coccidiosis. Determinations of numbers of oocysts discharged, quantities of feces discharged, feed consumption, and weight gain were made for female and male lambs in each group. The effect of experimentally induced and naturally occurring coccidiosis on the performance of each group was compared. Nonmedicated lambs, experimentally inoculated with Eimeria ninakohlyakimovae, gained the least weight. Lambs naturally infected with coccidia gained next best and inoculated lambs, in 2 groups medicated with 10 or 20 ppm of monensin in the feed, gained best. The average net gain for the 4 groups was 7.8, 9.7, 13.7, and 13.7 kg. The medicated lambs required less feed/kilogram of weight gain than did the nonmedicated lambs. In general, female lambs were more severely affected by the coccidia, consumed more feed, produced more fecal material, and gained less weight than did male lambs.     

Efficacy of Sarafloxacin in Broilers after Experimental Infection with Escherichia coli

Infections of chickens with Escherichia coli serotypeO78 can be treated with the antibiotic sarafloxacin. Three experiments were conducted on the administration of this drug to chickens that had been experimentally infected with E. coli. The birds were monitored for 10 days after infection for their average daily gain (ADG) and feed conversion ratio (FCR), and the post-mortem pathology was assessed. In the first experiment, sarafloxacin (20 mg/L, equivalent to 5 mg/kg live weight per day), given in the drinking water for 3 days after infection, led to a reduction in the mortality from 75% to 27%, but the ADG of the treated birds was still less than that of the uninfected controls. In the second experiment, when the sarafloxacin was administered at the same dose in the water but over only 2 h, there was also a considerable reduction in mortality, and the ADG and the FCR also improved significantly. In the third experiment, the dose dependence of the drug was tested. The birds were given 5 and 10 mg/kg per day sarafloxacin in each group, starting within 2 h after infection. This rapid administration of the drug completely prevented mortality, while the ADG and FCR were similar to those of the uninfected controls.     

Circulating prolactin concentrations in chickens infected with Eimeria tenella

50000 oocysts of Eimeria tenella were inoculated into three-week-old cockerels and the effect of the infection (coccidiosis) on circulating concentrations of glucose, prolactin, sodium, potassium and haematocrit was determined. At day 5 of infection haematocrit was reduced and glucose was increased. From day 7 onwards prolactin concentration was elevated in infected birds compared with control and pair-fed birds. Plasma electrolytes were unchanged. It appears likely that loss of water resulting in osmotic changes during infection is the major reason for the observed changes in prolactin concentration in infected cockerels.     

Effects of dietary tannic acid and vaccination on the course of coccidiosis in experimentally challenged broiler chicken

An experiment was carried out to assess the influence of tannic acid (TA) on integrity of the intestine in broiler chicks vaccinated against coccidiosis and challenged with the disease. In a 2 × 2 factorial design, the trial had five groups of 10 chickens each, including positive (group 2) and negative (group 1) controls. The chickens were kept on wood shavings and fed a commercial maize and soybean-based starter-grower diet. From day 1, groups 3 and 5 received TA (10 g kg(-1)) in their diet. On day 4, birds of groups 4 and 5 were vaccinated orally against coccidiosis with anti-coccidial vaccine, Livacox T?. Each dose of the vaccine contained 300-500 sporulated oocysts of each of Eimeria acervulina, Eimeria maxima and Eimeria tenella. On day 18, all experimental groups except for the negative (group 1) were challenged with 10-fold dose of Livacox T? to produce a mild coccidiosis infection. Faecal samples of individual birds were collected on day 23, and the number of faecal oocysts was determined. d-Xylose absorption test was also carried out on all birds on day 23. Immediately after d-xylose absorption test, all birds were killed humanely and the intestinal tract was removed, weighed and examined for gross lesions. Results showed that negative (group 1) and positive controls (group 2) had the highest and lowest levels of plasma d-xylose post-ingestion of the substrate, respectively. Vaccination and/or feeding TA raised the level of plasma d-xylose in infected birds, although this was not significant for TA-fed birds. Vaccination reduced but TA increased the total number of oocysts per gram of faeces. Birds of groups 2-5 had distinct intestinal lesions when compared with group 1. However, vaccination prevented intestinal lesions. Relative weights of intestinal parts were the lowest in group 1 and the highest in group 2. Vaccination but not TA reduced the relative weights of intestinal parts in infected birds. It was concluded that dietary tannins may reduce the efficacy of anticoccidial vaccines and alter the proper development of immunity against the disease.