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.     

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.     

"禽球灵"抗鸡球虫病的正交试验

由于目前抗球虫化药耐药性的不断出现和药物有害残留的日益困扰，研究和开发用绿色无公害的中草药防治鸡球虫病便显得十分重要。笔者经过多次试验研究发现，由常山、柴胡、地榆和绞股蓝组成的中药复方——“禽球灵”具有较好的抗球虫效果，为了搞清四种分在组方中所起的作用，以及各组分间的最佳用药配比，首次应用正交试验的方法进行了研究分析。     

Assessment of dietary supplementation with probiotics on performance, intestinal morphology and microflora of chickens infected with Eimeria tenella

We evaluated the effects of dietary supplementation with different preparations of probiotics on the performance of broiler chickens experimentally infected with 2 × 10(4) sporulated oocysts of Eimeria tenella at 14 days of age. Three hundred, day-old, Cobb-500 chicks, as hatched, were separated into 10 equal groups with three replicates. Two of the groups, one challenged with E. tenella oocysts and the other not, were given a basal diet and served as controls without medication. The other challenged groups were given the anticoccidial lasalocid (60 mg/kg) or Enterococcus faecium (5 × 10(8) or 5 × 10(9)cfu/kg feed), Bifidobacterium animalis (5 × 10(8)cfu/kg feed), Lactobacillus reuteri (5 × 10(8)cfu/kg feed), Bacillus subtilis (5 × 10(8)cfu/kg feed), or a multi-species probiotic mix at 5 × 10(8) or 5 × 10(9)cfu/kg feed, respectively. The trial lasted 6 weeks. Individual body weight, feed intake per pen and feed conversion ratio values were recorded weekly, along with the extent of bloody diarrhea, excreta oocyst numbers and bird mortality. Caecal lesions were assessed and intestinal samples were taken for histopathological and bacteriological evaluation from ileum and caecum. Overall growth performance of chickens fed the multi-species probiotic mix at both levels was higher (P<0.05) compared to the infected control. Overall oocyst shedding was lowest (P<0.05) in the lasalocid supplemented group. Villous height was higher (P<0.05) in Bacillus supplemented groups compared to infected controls. The Lactobacillus supplemented group had the highest (P<0.05) numbers of both Lactobacillus and Bifidobacterium in ileum and caecum. In conclusion, dietary probiotics are promising for further investigation on improving intestinal health and growth performance of broiler chickens experimentally challenged with E. tenella.     

Protective immunity enhanced by chimeric DNA prime-protein booster strategy against Eimeria tenella challenge

In an attempt to investigate the immune efficacy ofa DNA prime-protein booster strategy against avian coccidiosis with a chimeric construct, the Eimeria tenella antigen gene (3-1E) and chicken interferon gamma gene (ChIFN-gamma) were subcloned into the mammalian expression vector proVAX forming the plasmids proE and prol, and then linked by splicing overlap extension by polymerase chain reaction to construct the chimeric plasmid prolE; the chimeric protein (rlE) was expressed in Escherichia coli harboring the constructed plasmid pGEX/IE. Broilers were administered two intramuscular injections with the constructed DNA vaccines (50 microg); in the protein booster groups 100 microg of the rlE were given following the proIE prime. After challenge the proIE-vaccinated chickens showed the protective immunity as demonstrated by significantly reduced oocyst shedding compared with chickens immunized with proE, but the prolE vaccine did not have an additive effect of increasing antibody titer and body weight gain. The chickens in the rlE booster groups had significantly higher specific antibody responses than those immunized with prolE, and displayed further decreased oocyst shedding and increased body weight gain. Taken together, these results indicate that ChIFN-gamma exerts an adjuvant effect coexpressed with 3-1E and provide the first evidence that the DNA prime-protein booster strategy is able to augment the protective efficacy of chimeric DNA vaccine against challenge with Eimeria tenella.     

柔嫩艾美耳球虫杂交株对亲本株的免疫保护性研究

为探讨柔嫩艾美耳球虫杂交株对亲本株的免疫保护性,本研究用柔嫩艾美耳球虫(Eimeria tenella)杂交株及其亲本广州株、长春株、黑龙江株分别对AA肉鸡进行免疫和攻虫,通过OPG计数、粪便计分、盲肠病变计分、增重测定和保护率等指标评价免疫保护效果。结果表明E.tenella杂交株对其亲本广州株、长春株、黑龙江株的感染具有较强的免疫保护效果,保护率分别为83.9%、79.1%和81.2%;杂交株免疫肉鸡的盲肠病变计分和粪便计分显著低于广州株、长春株和黑龙江株(p0.05)。杂交株免疫后的肉鸡再用亲本株攻虫,采血进行CD4+T、CD8+T细胞检测,结果杂交株能引起两种T细胞数量增加,表明CD4+T、CD8+T细胞在球虫免疫中起着重要作用。     

Acquired immunity to Eimeria tenella in lasalocid-treated chickens

The effect of restricted medication with lasalocid sodium on the development of acquired immunity against Eimeria tenella was evaluated. The medication was allowed for all or part of 6-day test period (one day before until 4 days after infection). The parameters used for such evaluations were lesion score, caecal, bursal and splenic weights. The optimum treatment time for the drug was clearly indicated by lesion score which was very low when the medication was initiated 1 day before until 1 day after inoculation, but only partly effective if given on Day 2 post-inoculation. The challenge with higher doses on 14th day of immunizing infection revealed a reverse picture where the higher lesions were recorded by the groups where medication was started earlier than the delayed treatment groups. This indicates partial interference with the development of immunity in the earlier treatment groups. Birds treated on Day 4 p.i. were not significantly different (P less than 0.05) from the infected unmedicated control group, suggesting no interference in acquired immunity. A correlation was noticed between day of treatment, the lesion score and weight gain of the caecum as well as the spleen. After both immunizing and challenge infections, the bursa did not show any significant variation in weight, whereas the weight of the spleen did vary. The infected unmedicated group and the delayed-treatment groups had a comparatively higher splenic weight than the uninfected unmedicated group of birds.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of Natustat supplementation on performance, feed efficiency and intestinal lesion scores in broiler chickens challenged with Eimeria acervulina, Eimeria maxima and Eimeria tenella

The effects of dietary supplementation of Natustat™, a propriety plant derived product (Alltech Inc., KY, USA) and Salinomycin, on performance, feed efficiency and intestinal lesion scores were observed during two Eimeria challenge trials in broiler chickens. In the first trial chickens were challenged with Eimeria sp. via infecting the litter with a known amount of Eimeria oocysts. In the second trial the source of the Eimeria challenge was the litter from the first trial and the same treatment groups were assigned to the same pens as in the initial trial.

Birds were placed 55 per pen with seven pens per treatment. Performance parameters were recorded on days 21 and 42 during both trials. Intestinal lesion scores were assessed on days 14 and 21 during Trial 1 and on day 21 during Trial 2. Average weight gain and feed conversion ratios were significantly improved in the Natustat™ and Salinomycin treatment groups when compared to the non-supplemented infected group. Furthermore, lesion scores were lower on all sampling days in the Natustat™ and Salinomycin groups when compared to the non-supplemented group. However, only lesions associated with Eimeria tenella were significantly lowered by Natustat™ and Salinomycin supplementation.

Natustat™ and Salinomycin were equivalent in alleviating the negative performance effects associated with coccidiosis challenge. In summary, Natustat™ has the potential to be used as a natural alternative to chemotherapeutic drugs for Eimeria control.     

柔嫩艾美耳球虫TA4重组抗原的免疫试验

构建了能表达柔嫩艾美耳球虫TA4抗原的重组质粒,使其在乳球菌中表达。用刚出壳的健康雏鸡为实验对象,对乳球菌表达的TA4重组抗原进行免疫效果的研究。用表达球虫TA4抗原的工程乳球菌以5×108个/(只·d)的剂量给雏鸡口服10d,同时设置乳球菌组、未免疫未攻毒组和未免疫攻毒组作对照,于11日龄用5×104个强毒卵囊进行攻毒。结果表明TA4重组抗原组抗球虫指数为160.12,实验鸡可获得一定免疫保护力。     

中草药和球敌对鸡感染柔嫩艾美耳球虫后血清生化指标的影响

将160只14日龄雏鸡随机分为未感染对照组(Ⅰ)、感染对照组(Ⅱ)、中草药组(Ⅲ)和球敌组(Ⅳ),每组40只.除Ⅰ组外,其余3组每只鸡口服感染8.0×10~4个E.tenella孢子化卵囊,于感染当天,Ⅲ、Ⅳ组鸡分别饮用有效质量浓度为10 g/L和1 mg/L的抗球虫中草药饮水剂和球敌,连用12 d.对球虫感染0、3,6、9、12 d时的血清TP、ALB、Tg、UA、Cre、MDA含量和LDH、ALP、SOD、GSH-Px、CAT活性的动态变化进行测定.结果表明:与Ⅱ组鸡比较,Ⅲ、Ⅳ组血清TP含量于感染后6、9 d分别显著提高了22.31%(P<0.05)、33.57%(P<0.05)和17.48%(P<0.05)、24.23%(P<0.05);在感染后6 d,ALB含量提高了26.17%(P>0.05)和48.23%(P<0.05),Tg含量也显著提高了49.25%(P<0.01)和40.30%(P<0.01).而UA含量在感染后3 d显著降低了42.39%(P<0.01)和42.48%(P<0.01);LDH活性于感染后3、6 d分别降低了30.77%(P<0.01)、30.13%(P<0.01)和23.36%(P<0.05)、21.21(P<0.05);NO含量和iNOS活性于感染后6 d分别降低了36.18%(P<0.01)、29.91%(P<0.05)和14.25%(P<0.01)、12.36%(P<0.05).虽然Cre,MDA含量及ALP、SOD、GSH-Px、CAT活性与Ⅱ组比较差异不显著,但在感染高峰期(6 d),Cre、MDA含量和ALP活性分别降低了17.51%、12.52%,9.21%、14.58%和16.92%、14.39%,而SOD、GSH-Px、CAT活性分别提高了5.65%、7.33%,15.01%、19.82%和65.97%、52.08%.与Ⅰ组比较,除UA、Cre含量和SOD活性差异显著(P<0.05或P<0.01)外,其他指标均无显著差异.提示:中草药和球敌通过抵抗球虫感染,在一定程度上有助于保持血清生化指标的相对恒定.     

Immunization of young chickens by trickle infection with Eimeria tenella.

Immunization of chickens was attempted with low levels of Eimeria tenella oocysts (50 oocysts per day) over the first 1 or 2 weeks of life--the "trickle infection" (TI) method. When chickens were immunized by TI at 0-13 days of age, no cecal lesions and a reduced number of oocysts in ceca were observed after challenge at 17 days of age. TI at 0-6 days of age conferred better protection against challenge with E. tenella than did TI at 7-13 days. However, cecal lesions were observed in almost all of these chickens. These findings indicated that TI for 2 weeks (0-13 days of age) provided better immunity than TI for 1 week (0-6 or 7-13 days of age).     

Comparative effect of dietary supplements on the performance and severity of experimental Eimeria tenella infection in broiler chickens

Tropical Animal Health and Production - This study evaluated the productive and reproductive performance of Charolais cows with different body mass index (BMI) at calving and the development of...     

Physiologic basis of blood loss during Eimeria tenella infection

Eimeria tenella-induced hemorrhage resulted in total blood losses of up to 10% of the body weight. Although packed cell volume was reduced 50%, neither plasma volume nor blood volume was significantly decreased, except briefly. The retention of lost blood in the ceca varied with the strain of E. tenella. Chicks infected with laboratory strain (L.S.) 24 passed most of the blood into the feces, whereas those infected with L.S. 49 retained most of the blood within the ceca.     

Coccidial infection with Eimeria tenella and caecal defaecation in chicks.

1. The periodicity of caecal defaecation was investigated in chicks infected with Eimeria tenella. The birds were illuminated for 12 h/d (07.00-19.00) and faeces were collected at 3-h intervals for up to 21 d. 2. In uninfected birds caecal faeces were never collected during the dark period. During the periods 07.00-10.00 h, 10.00-13.00 h, 13.00-16.00 h and 16.00-19.00 h, caecal defaecation occurred on approximately 44, 19, 55 and 91% of the total number of days respectively. 3. In infected birds production of haemorrhagic caecal faeces began from between 90 and 156 h after infection and continued during both light and dark periods for between 12 and 48 h. After this period, no caecal faeces were observed for between 39 and 120 h. Normal caecal defaecation resumed from between 198 and 264 h.     

硝唑尼特混悬液对鸡柔嫩艾美尔球虫病治疗效果研究

采用人工接种柔嫩艾美尔球虫孢子化卵囊的方法复制鸡球虫病模型,检测发病率、死亡率、存活率、增重量等指标,研究硝唑尼特混悬液对鸡球虫病的临床治疗效果.结果显示,高、中、低剂量的硝唑尼特抗球虫指数分别为163.6、168.3、137.9;硝唑尼特混悬液与癸氧喹酯对照组相比差异显著(P＜0.05),与妥曲珠利对照组相比差异不显著(P＞0.05);硝唑尼特混悬液高剂量组和中剂量组差异不显著(P＞0.05),抗球虫指数为中效,低剂量组的抗球虫指数为低效.试验证明,硝唑尼特混悬液对鸡柔嫩艾美耳球虫病具有一定的治疗效果,有望开发为新的抗球虫药物.     

不同地理株及其杂交株柔嫩艾美耳球虫细胞免疫水平研究

本文首先培育了5个不同虫株柔嫩艾美耳球虫(Emeria tenella):3个不同地理株吉林株[J]、山东株[S]、黑龙江株[H]和2个杂交株F1(山东株×黑龙江株)、F2(F1×吉林株).将300只AA肉鸡鸡雏随机分成6组,每组50只,12日龄时分别用不同株柔嫩艾美耳球虫进行免疫,首免剂量为1 × 104卵囊.24日龄时攻虫,剂量为1×104卵囊.攻虫后10日龄时翼下静脉采血1 mL检测学液中的CD4 ,CD8 的数量,以此判断柔嫩艾美耳球虫的细胞免疫功能,结果证明:杂交株柔嫩艾美耳球虫CD4 ,CD8 的数量远远高于其它组,F2组更高.各组的CD4 ,CD8 的数量依次为F2＞F1＞S＞H＞J. CD4 ,CD8 的数量的比值也不同.即各组的细胞免疫功能不同,从数值上反应出,F2株细胞免疫水平最高,其次是F1,再次是山东株,黑龙江株和吉林株最低.     

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.     

白头翁提取物对鸡抗柔嫩艾美耳球虫感染的效果研究

选用超声法、渗漉法以及水煎法提取白头翁药效组分,超声法和渗漉法采用L9(34)正交设计。在试验前进行柔嫩艾美耳球虫卵囊毒力测定试验,建立鸡感染模型。通过比较存活率、相对增重率、盲肠病变值、卵囊值和抗球虫指数(ACI)以及药效指数来判定白头翁提取物的抗球虫效果。结果发现每只鸡感染8万孢子化卵囊效果较理想;超声提取物UEb、UEc、UEd组相对增重率较高,分别为99.6%、101.6%、100.6%,均明显高于感染对照;所有提取物中超声提取物UEb的ACI最高,为165.6,感染对照ACI值仅为77.9。     

Guar meal ameliorates Eimeria tenella infection in broiler chicks

Guar meal contains relatively high levels of saponins, which are known to have antiprotozoal activity and may be effective against coccidiosis. A 2x2 factorial experiment investigated the impact of guar meal (0 or 5%) corn-soy-based starter broiler diets on chicks unchallenged or challenged with Eimeria tenella. At 1 day of age, 120 unsexed RossxRoss broiler chicks were randomly distributed among four treatment groups. Chicks were challenged with 5x10(3) sporulated oocysts of E. tenella in 0.5ml at 10 days of age by oral gavage. Weekly body weight, body weight gains, feed conversion ratio and mortality rate were recorded for chicks fed from 0 to 21 days of age. Oocysts shed per gram feces were recorded from 6 to 10 days post-challenge. Results showed that challenged chicks fed 0% guar meal had significantly higher oocysts per gram shed in feces than the other groups. No significant differences among treatment groups in mortality rate were observed. Body weights of unchallenged and challenged chicks fed 0% guar meal were significantly higher than those fed 5% guar meal at 2 weeks of age. Results indicated that including 5% guar meal in the diet of chicks challenged with E. tenella decreased oocysts shed per gram feces and prevented bloody diarrhea, but without affects on body weight and feed conversion ratio at 11 days post-challenge.