Genetic variability of the resistance for three types of enteropathy in the growing rabbit

This paper describes the genetic variability for the resistance to three digestive stresses in the growing rabbit: after inoculation of coccidia (trial “coccidia”), with a fibre deficient diet (trial “FD”), and after experimental reproduction of epizootic rabbit enteropathy (trial “ERE”). Genetic variability was analysed from a sample of 48 sires, which produced the experimental young rabbits. These animals were examined on D0, D4, D11, D18, D25 and D32 after weaning (at 30 days old). Three clinical symptoms were checked: bloated abdomen, diarrhoea and mucus. Mortality and clinical symptoms were used to assess an individual response to each digestive stress. Two binary indexes were defined to describe this rabbit individual response. The first one (“Alive”) dealt with mortality. The second (“Tolerant”) dealt with mortality and morbidity. “Alive”, and “tolerant” percentages were low for the “coccidia” trial (61% and 23% respectively), high for the “FD” trial (75% and 36% respectively) and intermediate for the “ERE” trial (66% and 37% respectively). The sire effect was significant for each index in the “coccidia” and the “FD” trials. The sire effect was significant for the “tolerant” index in the “ERE” trial. Correlations between sire rankings for the two indexes of one trial were often significant. Correlations between sire rankings for indexes of “coccidia” and “FD” trials were weakly significant. Our results demonstrate that there is a genetic variability for the resistance to three different enteropathies.     

Use of contrast‐enhanced ultrasonography in the diagnosis of a liver lobe torsion in a rabbit (Oryctolagus cuniculus)

A 1‐year‐old male French Lop rabbit (Oryctolagus cuniculus) was presented with a sudden onset of hyporexia. Physical examination revealed cranial abdominal discomfort. Liver enzymes were elevated on serum biochemistry profile. Abdominal radiographs showed diffusely gas‐dilated small intestinal loops. On abdominal ultrasound, a lobe in the right aspect of the liver was hypoechoic with rounded margins and was surrounded by hyperechoic fat and anechoic fluid. Contrast‐enhanced ultrasonography showed complete lack of perfusion in the abnormal right liver lobe. Exploratory laparotomy revealed torsion of the quadrate liver lobe. Diffuse coagulation necrosis was noted on histopathologic examination. The rabbit fully recovered after surgery.     

Dynamics and responsiveness of T-lymphocytes in secondary lymphoid organs of rabbits developing immunity to Eimeria intestinalis

Primary infection with Eimeria intestinalis confers very effective immunity against further infections in rabbits. This study was designed to determine the onset of the immune response in primary-infected rabbits and to characterise the immune status of protected rabbits. Variations in kinetics of CD4+ and CD8+ T-cell subpopulations were followed after primary infection at the intestinal sites of penetration (duodenum) and development (ileum), in mesenteric lymph nodes (MLN) and in the spleen. The response against the parasite was measured by specific lymphocyte proliferation in the spleen and MLN and by determining specific IgG titres in serum. The mucosal immune response was strong after primary infection and was characterised by (i) transient increase in the percentages of intestinal CD4+ lymphocytes and MLN CD8+ lymphocytes 14 days PI and (ii) strong increase in the percentages of intestinal CD8+ lymphocytes from 14 days PI persisting throughout further infections. Extensive infiltration of the lamina propria with CD8+ lymphocytes was observed 14 days PI. The specific proliferative response started between 7 and 14 days PI in MLN but remained undetectable in spleens for up to 21 days, in contrast to “immunised” rabbits. The fact that systemic immune responses were low after primary infection, in contrast to indicators of mucosal immune responsiveness, suggests that protection of rabbits against E. intestinalis infection is due to an effective mucosal immune response, and that systemic responses that increase after successive infections are only reflections of repeated encounters with parasite antigens.     

假蒟提取物对感染柔嫩艾美耳球虫鸡血液指标的影响

本试验旨在研究假蒟提取物对感染柔嫩艾美耳球虫鸡血液指标的影响。270只1日龄海南文昌公鸡,随机分为6个组,每组3个重复,每重复15只,T1、T2和T3组为对照组(依次分为不感染不给药组、感染不给药组、感染给药组);T4、T5和T6组为假蒟添加组,分别在基础日粮中添加200、400、600mg/kg假蒟提取物粉剂。15日龄时,每组随机抽取30只鸡,除T1组灌服生理盐水外,其他各组鸡均经口接种柔嫩艾美耳球虫卵囊悬液,分别于接种前1d,接种后3、6、9d清晨采血测定其血液指标。结果表明,与感染球虫不给药的T2组相比,假蒟组(T4、T5、T6)可以显著降低感染球虫鸡粪便中球虫卵囊值(P0.05)。假蒟组在感染球虫后第6天,与T1组比,RBC、HGB、HCT、Ca2+、Na+、Cl-、TP、ALB、GLB、TG、CHOL、T4等指标呈下降趋势;但在感染球虫后第9天,TP、GLB含量均显著高于T1组(P0.05);在感染球虫后第6天,假蒟组与对照组相比,ALT、AST浓度水平均显著降低(P0.05)。结果提示,假蒟提取物能提高感染球虫后鸡机体免疫机能,降低肝脏损伤,降低鸡感染球虫后粪便卵囊值,具有一定的抗球虫效果。     

四种兔艾美耳球虫卵囊产量的比较

分别用4种兔艾美耳球虫经口接种45日龄无球虫感染兔,接种剂量为1×104个卵囊/兔。感染后4d～20d,以麦克马斯特氏法计数每天排出的卵囊。结果表明,肠艾美耳球虫排卵量最多,为365.76×106个,中型艾美耳球虫为317.26×106个、黄艾美耳球虫为304.36×106个,大型艾美耳球虫排卵量最少,为200.12×106个。大型艾美耳球虫在感染后第6.5天有卵囊排出,第10.5天达到高峰(66.50×106个/只),占总量的33.23%;肠艾美耳球虫在感染后第9天有卵囊排出,第13天达到高峰(138.40×106个/只),占总量的37.83%;黄艾美耳球虫在感染后第9天有卵囊排出,第11天达到高峰(102.80×106个/只),占总量的33.78%;中型艾美耳球虫在感染后第4.5天有卵囊排出,第6.5天达到高峰(167.8×106个/只),占总量的52.89%。     

Relative virulences of a drug-resistant and a drug-sensitive strain of Eimeria acervulina, a coccidium of chickens

The virulence of a field strain of the chicken coccidian parasite Eimeria acervulina (Boreham I), dually resistant to the chemically unrelated anticoccidial agents decoquinate and clopidol, was compared with that of a drug-sensitive laboratory strain (Ongar) of the same species. Following a single heavy infection (prevented from recycling), both strains exhibited pathogenic effects typical of their species, viz., pathognomonic lesions, adverse effects on body weight gain and feed conversion ratio (FCR), but no mortality. One week after infection, chicks infected with either strain had a statistically significantly worse weight gain than the uninfected control; the Boreham I strain produced more oocysts, and caused slightly more severe duodenal lesions and poorer FCRs than the Ongar strain (all those effects being non-significant). After 3 weeks, there were no significant differences between any cumulative effects of either strain, nor any differences from the uninfected control. However, from 2 to 3 weeks after infection, chicks infected with either strain had a greater feed consumption and growth rate than uninfected chicks. When chicks reared on solid floors were given lighter infections of either strain, which were allowed subsequently to recycle naturally, there were no consistent reductions in weight gains, but feed consumption was higher than that of uninfected chicks. Whatever, the mode of infection, there were no significant differences between the weights of infected and uninfected chicks after 3 weeks, but the FCR of infected chicks was usually poorer than that of uninfected chicks. The difference between the virulences of the Boreham I and Ongar strains was not greater than that between various drug-resistant strains or between various sensitive strains of several Eimeria species recorded in the literature. It is therefore concluded that there was no difference between the virulences of the two strains of E. acervulina that could be attributed to the drug-resistance of one of them.     

兔球虫病的危害及防治进展

本文对兔球虫病的病原种类、流行特征、症状、诊断、疫苗免疫及防治等进行了综述,旨在为有效防控兔球虫病提供参考。     

Epidemiological Investigation and Species Identification of Eimeria of a Rex Rabbit Farm in Fujian Province

In order to investigate coccidium infection of a Rex rabbit farm in Fujian province, 494 fecal samples were collected from different ages of Rex rabbits and examined by McMaster's method and the method of saturated saline flotation.The results showed that the total prevalence was 87.45% and the mean oocysts per gram (OPG) value was 2.56×10⁴.The prevalences of coccidia among each rabbit age were different, and it was highest at the age of about 40 d (98.61%) and about 65 d (98.95%) rabbits.The prevalence and OPG values at the age under 30 d (19.23% and 331) were significantly lower, and the distribution pattern of OPG values was negative binomial distribution in rabbits by using fitting of distributions.In total, 11 species of Eimeria were identified from oocyst-positive samples.The infection of Eimeria was mixed infection with more than two Eimeria species, and mostly of which were infected by 3 to 7 Eimeria species.The dominant species of Eimeria were E.perforans, E.media, E.exigua and E.magna, and their prevalences were 20.15%, 16.79%, 13.94% and 13.48%, respectively.     

福建某獭兔场兔艾美耳球虫感染情况调查及种类鉴定

为掌握福建某规模化獭兔场兔球虫病的流行情况,采用麦克马斯特计数法(McMaster's method)和饱和氯化钠溶液漂浮法,对采集的494份獭兔粪便样品中兔球虫感染情况和卵囊种类进行调查分析。结果显示,该獭兔场兔球虫总感染率和平均每克粪便卵囊数(OPG值)分别为87.45%和2.56×10⁴,各日龄段均有感染,其中以40日龄左右兔和65日龄左右兔感染率最高,分别达98.61%和98.95%;30日龄以下哺乳仔兔感染率和OPG值均最低,分别为19.23%和331,且该场兔球虫卵囊的OPG值分布符合负二项分布。本次调查共检出11种兔艾美耳球虫,均为混合感染,感染球虫种类多为3~7种;其中感染比例最高的4种兔球虫依次为穿孔艾美耳球虫(20.15%)、中型艾美耳球虫(16.79%)、小型艾美耳球虫(13.94%)和大型艾美耳球虫(13.48%)。     

齐卡肉兔球虫种类调查研究

对西宁市某种兔场进行了球虫种类调查，发现兔艾美尔球虫8种：穿孔艾美尔球虫、大型艾美尔球虫、中型艾美尔球虫、小型艾美尔球虫、无残艾美尔球虫、盲肠艾美尔球虫、斯氏艾美尔球虫和梨形艾美尔球虫，其中以穿孔艾美尔球虫所占比例最高，为55.5%，其次为大型艾美尔球虫，占17.5%，中型艾美尔球虫占11.5%，盲肠艾美尔球虫占8%。观察、研究了卵囊的形态、大小、颜色、内部构造及孢子化时间等。     

微生物制剂对幼兔腹泻治疗的研究

本实验从健康家兔肠道正常菌群中经分离、鉴定,筛选出3种有益菌种:需氧芽孢杆菌、酵母菌和厌氧乳酸杆菌,经安全试验和药物敏感试验合格后,分别发酵培养,制成复合型微生物制剂再应用到断奶幼兔中,观察对幼兔体重、消耗饲料量、腹泻发生率等的影响,同时应用微生物制剂治疗腹泻兔,观察其治疗效果。实验表明,应用复合微生物制剂增重效果明显,料肉比分别为4.20:1,50日龄和70日龄的成活率分别为96%和90.67%,第50日龄和第70日龄时腹泻率为1.33%和4.67%。使用兔源菌种制成的Ⅰ型微生物制剂能够减少家兔的耗料量,体重明显增加,显著降低料肉比;能够较好地预防幼兔腹泻的发生和降低死亡只数,并且制剂的菌种对大多数抗生素没有抗药性,具有促进生长、减少或杜绝药物污染的优点。     

兔出血症病毒衣壳蛋白VP60与兔肝脏细胞中相互作用蛋白的初步筛选

为鉴定兔出血症病毒(RHDV)在感染兔肝脏过程中与肝细胞膜表面相互作用的靶蛋白,本研究利用SMART文库构建技术构建了兔肝脏细胞的真核表达cDNA重组质粒文库,将其转染SP2/0细胞,经嘌呤霉素筛选表达兔肝细胞蛋白的阳性SP2/0细胞.以RHDV-VP60蛋白作为固相包被抗原,经筛选,获得能够与VP60蛋白相互结合的表达性阳性SP2/0细胞克隆.测序表明26个克隆与兔的一些功能性蛋白有较高的同源性,其中包括代谢酶类13个、免疫信号通路受体蛋白5个以及其他细胞膜蛋白等.本研究鉴定的与RHDV VP60具有结合性的细胞蛋白为RHDV感染机制的研究奠定了基础.     

家兔黄艾美耳球虫血清抗体ELISA检测法的建立

应用制备的孢子化卵囊可溶性抗原作了包被抗原建立了兔球虫血清抗体的ＥＬＩＳＡ检测法。其最适条件为：抗原包被浓度，２００μｇ／ｍＬ；包被温度，３７℃（２ｈ）；血清反应时间，１．５ｈ；酶标抗体标准工作浓度，１：１０００；反应时间，１ｈ待检血清稀释度，１：１００：ＥＬＩＳＡ试验的规定吸收值为０．０６，孢子化卵囊可溶性抗原比非孢子化卵囊可溶性抗源更适于作为ＥＬＩＳＡ包被抗原。     

Hyperostotic polyarthropathy in a rabbit - a suspected case of chronic hypervitaminosis A from a diet of carrots

Chronic hypervitaminosis A can occur in many species after excessive dietary intake of Vitamin A (retinol). The most common presentation of chronic hypervitaminosis A is a polyarthropathy with hyperostosis and ankylosis of various joints. This case report describes a probable case of naturally occurring hypervitaminosis A-induced polyarthropathy in a rabbit after chronic ingestion of a diet made up almost exclusively of carrots. Carrots do not contain retinol, but are rich in provitamin A (or beta-carotene). Rabbits are unique in that they can convert 100% of dietary beta-carotene into retinol. A syndrome of naturally occurring hypervitaminosis A-induced polyarthropathy has not been described in a rabbit before.     

Epizootic rabbit enteropathy: comparison of PCR-based RAPD fingerprints from virulent and non-virulent samples

Epizootic rabbit enteropathy is a gastrointestinal disorder of unknown aetiology of farmed rabbits characterised by inanition and mortality. Genomic analyses of virulent and non-virulent samples of inocula were performed using random amplification of polymorphic DNA (RAPD). Differences in bacterial DNA composition were found between inocula, but specific sequences were not linked with field cases of epizootic rabbit enteropathy.     

几种抗球虫药物对獭兔球虫感染和幼兔生长性能的影响

在福建省福安市某獭兔场共检测出16种艾美耳球虫,均为混合感染。选取210只断乳1周、球虫卵囊阳性的獭兔幼兔,随机分为7组,进行抗球虫药物试验。在抗球虫药物试验组中,2.5%妥曲珠利组的獭兔幼兔按有效剂量30 mg/kg体重、5%肠球双效(盐酸氨丙啉+胺喹噁啉钠)组和5%优球乐(癸氧喹酯)组按有效剂量50 mg/kg体重灌服,分为1次用药组和2次用药组;对照组灌服等量生理盐水。结果显示,妥曲珠利组獭兔幼兔用药后第1周,粪便中的球虫卵囊数(OPG值)比用药前减少78.39%,也显著低于其他药物组和对照组(P<0.01);用药后第2周,球虫OPG值比用药前减少88.35%,感染率也降至最低;用药后第8周,粪便中球虫OPG值比用药前减少92.99%。至用药后第8周,各试验组与对照组獭兔幼兔球虫OPG值均转归为相对较低水平,感染率则仍保持较高水平;妥曲珠利组獭兔幼兔死亡率显著低于对照组(P<0.05),其他组间死亡率差异不显著;其平均增重显著高于对照组(P<0.05),料重比则显著低于对照组(P<0.05)、极显著低于5%肠球双效1次用药组(P<0.01)。