Myxomatosis of the Depilated Angora rabbit. A Preliminary Study

Abstract— A nodular eruption occurring on the skin of depilated Angora rabbits was studied at 47 rabbit farms in 1988. Virus isolation, electron microscopy, transmission experiments and comparison with experimental infection using recognised strains of myxoma virus confirmed that the disease was myxomatosis. The disease occurred particularly in July and August in rabbits vaccinated in March or April with the heterologous vaccine. Morbidity on farms where lesions occurred only on depilated skin was much lower than on those where generalised forms occurred. In experimental intradermal infections of unvaccinated New Zealand White rabbits, both primary and secondary myxomas occurred earlier in inoculated animals depilated up to five days before or on the day of inoculation; but after six days development of lesions in the depilated area was not observed. The authors advance the hypotheses that the nature ot the spontaneous disease in rabbitries is dependant on the residual level of post-vaccinal immunity. Where this is high, myxomatosis does not occur. Where it is low classical myxomatosis, with numerous lesions on the depilated skin, occurs. Intermediate levels of immunity are able to restrict the development of myxomas to the depilated area. Résumé— Des nodules cutanés, se développant exclusivement sur le dos de quelques animaux récemment épilés, ont été observés en 1988 dans 47 élevages de lapins angora. L'isolement viral, la microscopie électronique, la transmission expérimentale et la comparaison avec l'infection expérimentale par des souches de virus myxomateux ont permis de montrer qu'il s'agissait d'une forme particulière de myxomatose. La maladie était principalement observée en juillet et août sur des lapins vaccinés en mars et avril avec un vaccin hétérologue. La morbidité dans les élevages atteins était significativement inférieure à celle constatée dans les élevages affectés par des formes classiques de myxomatose. L'infection expérimentale de lapins néo-zélandais non vaccinés a montré que le développement des myxomes était plus précoce lorsque les animaux étaient épilés cinq jours avant ou le jour de l'inoculation; mais aucune lésion ne fut observée dans la zone épilée lorsque l'épilation avait lieu plus de six jours après l'inoculation. Les auteurs émettent l'hypothèse que l'aspect de la maladie dépend du niveau résiduel de l'immunité post-vaccinale. Si ce niveau est élevé, la maladie n'apparaît pas. S'il est insuffisant, on observe une forme classique de myxomatose, avec en plus de nombreux myxomes dans la zone cutanée épilée. Une immunité intermédiaire limite le développement des myxomes aux zones cutanées épilées. Zusammenfassung— Das Auftreten von Nodula auf der Haut von enthaarten Angorakaninchen wurde 1988 in 47 Kaninchenfarmen untersucht. Durch Virusisolierung, elektronenmikroskopische Untersuchungen, Übertragungsversuche und den Vergleich mit experimentellen Infektionen mit bekannten Myxomavirusstämmen konnte bestätigt werden, daß es sich bei der Erkrankung urn Myxomatose handelte. Die Ekrankung trat vor allem im Juli und August bei Kaninchen auf, die im März oder April mit heterologen Vakzinen geimpft worden waren. Die Morbidität in Betrieben, wo die Veränderungen nur auf enthaarter Haut auftraten, war viel niedriger als bei denen, wo generalisierte Formen auftraten. Bei experimentellen intradermalen Infektionen nicht geimpfter Weiße Neuseeland-Kaninchen traten sowohl primäre wie sekundäre Myxome früher auf bei den inokulierten Tieren, die bis zu fünf Tage vor der Inokulation depiliert worden waren; 6 Tage danach jedoch wurde keine Entwicklung von Veränderungen im depilierton Bereich festgestellt. Die Autoren stellen die Hypothese auf, daß der Grad der natürlichen Erkrankung in Kaninchenhaltungen von dom residualen Spiegel der durch Impfung erzeugten Immunität abhängt. Wo dieser Spiegel hoch ist, tritt die Myxomatose nicht auf. Wo er niedrig ist, kommt es zu der klassischen Myxomatose mit zahlreichen Veränderungen auf der enthaarten Haut. Mittlere Immunitätsspiegel können die Entwicklung der Myxome of enthaarte Gebiete beschränken. Resumen Una erupción nodular producida en la piel de conejos de Angora depilados fue estudiada en 47 granjas de conejos en 1988. El aislamiento de virus, microscopía electrónica, experimentos de transmisión y la comparación con infecciones experimentales usando cultivos conocidos del virus myxoma, confirmaron que la enfermedad era myxomatosis. La enfermedad ocurrió especialmente en julio y agosto en conejos vacunados en marzo o abril con la vacuna heteróloga. En infecciones experimentales intradérmicas de conejos no vacunados New Zealand y Blancos, ambos myxomas, primario y secundario ocurrieron más pronto en animales inoculados depilados hasta unos cinco dias antes o en el día de la inoculacion; pero después de seis días no se observó desarrollo de lesiones en el area depilada. Los autores avanzaron la hipotesis de que la naturaleza de la enfermedad espontánea en rabbitrios es dependiente del nivel residual de inmunidad post-vacunal. Dónde este es elevado no se produce myxomatosis. Dónde es bajo, se produce la clásica myxomatosis con numerosas lesiones en la piel depilada. Niveles intermedios de inmunidad son capaces de restringir el desarrollo de myxomas en el area depilada.     

Effects of mimosine and 2,3-dihydroxypyridine on fiber shedding in Angora goats.

The effects of intravenous infusion of mimosine or 2,3-dihydroxypyridine (2,3-DHP) and the effects of oral dose level of mimosine on fiber shedding in Angora goats were determined. In one experiment, 20 mature Angora wethers (36+/-1.9 kg BW) were infused for 2 d with 79, 102, or 135 mg/(kg BW.d) of mimosine, 90 mg/(kg BW.d) of 2,3-DHP, or saline. At 7 d after infusion began, fiber shedding was observed in all goats receiving mimosine but not in any goats infused with 2,3-DHP or saline. Fiber shedding varied among goats; in some goats, fiber shedding was complete and occurred without hand-plucking, whereas in others fiber was retained by nonshed fibers but could be removed by hand-plucking. Nonshed fibers were larger in diameter and more likely to be medullated (P < .05) compared with hand-plucked fibers. Mean plasma mimosine concentration at 24 and 48 h after infusion began was 79 and 98 micromol/L (P < .05), respectively, and greater (P < .05) for mimosine infused at 135 than at 102 mg/(kg BW.d) (89, 68, and 108 micromol/L for mimosine infused at 79, 102, and 135 mg/[kg BW.d], respectively; SE 9.5). In another experiment, oral dosing of eight Angora bucks (23+/-.5 kg BW) with 400 or 600 mg/kg BW of mimosine rapidly increased plasma mimosine concentration, which reached approximately 100 and 160 micromol/L at 5 h after dosing; however, periods of time during which plasma mimosine concentrations were comparable to those in the first experiment were considerably shorter. Oral mimosine dosing did not induce fiber shedding in 7 d. After 31 d, fiber was retained by nonshed fibers but could be removed by hand-plucking or could only be partially removed with difficulty by hand-plucking. There were no toxic effects of mimosine or 2,3-DHP administration; only minor, short-term inhibitions of feed intake by mimosine were noted in some goats. In conclusion, mimosine holds promise as a safe means to remove fiber of Angora goats; further research is necessary to characterize the seasonality of follicle activity and to develop convenient means of mimosine delivery.     

Genetic parameters for growth of fiber diameter in alpacas

The alpaca is the most important fiber producer of the South American camelid species, and is an important source of income for the Andean communities. Nowadays, fiber diameter is considered the main selection objective in alpaca populations throughout the world. However, fiber diameter increases with the age of the animals, and it would be preferable to select those animals that maintain a thin fiber throughout their life span. The goal of this study was to describe the genetic relationship between fiber diameter at weaning age (6 mo) and the evolution of fiber diameter along the life span. The analysis of the evolution of fiber diameter was studied as a useful model for canalization and as a longitudinal trait by hierarchical Bayesian analysis. The results suggested that substantial genetic variation exists for fiber diameter and also for the variability and linear growth of the fiber diameter. Thus, a genetic selection program is plausible to modify the evolution of fiber diameter with time, together with a favorable correlated decrease in fiber diameter.     

安哥拉山羊的遗传改良

与安哥拉山羊主要生产国相比,我国对安哥拉山羊的研究无论是在深度还是在广度方面都存在明显的差距,为保持安哥拉山羊在我国的持续稳定发展,对安哥拉山羊进行持续的遗传改良是必要的.作者在对安哥拉山羊的育种简史加以概述的基础上,就主要经济性状的遗传参数、杂交育种和选种方法作了综述,就存在的问题予以讨论,并提出可能的改进方法以指导我国的安哥拉山羊生产.     

家兔日粮粗纤维营养与调控

中国兔肉年产最已达到54万吨,约占世界总产量的45％,兔毛年产量600多万吨．而且养兔业仍呈上升趋势,可以说中国是个名副其实的养兔大国。在这种情况下．部分养殖户为了追求利益。在饲养中常像饲喂鸡、猪一样．以高能量、高蛋白日粮为主．以求提高日增重和兔毛产量,从而忽略了粗纤维的重要性,导致兔群发病率升高．如肠道功能紊乱、肠炎、腹泻、异食癖等,反而降低了经济效益。     

Prediction of clean mohair, fiber diameter, vegetable matter, and medullated fiber with near-infrared spectroscopy.

Four experiments were conducted in three separate years to test the utility of near-infrared spectroscopy (NIRS) to predict the clean mohair content of Angora goat fleece. Mohair fleece samples were obtained each year from yearling billies at the conclusion of the Angora Goat Performance Test conducted at the Texas A&M University Research Station, Sonora. In Exp. 1 (n = 293) and Exp. 2 (n = 256), fleeces were scanned with a Pacific Scientific (Silver Spring, MD) near-infrared spectrometer fitted with a fiber-optic probe, and calibrations were developed for clean mohair content. In Exp. 3, 59 mohair fleeces collected at the Texas A&M Research Station in San Angelo were sampled four times each. Each sample was scanned with the same spectrometer in reflectance mode fitted with a transport mechanism. This mechanism allowed the instrument to scan a 15-cm2 segment of the fleece sample. Conventional procedures to determine reference values for mohair yield, vegetable matter content, fiber diameter, and percentage of medullated and kemp fibers were conducted. Prediction equations were developed that related NIR spectra to reference values for yield and diameter parameters and were used to predict mohair characteristics for each fleece sample. The predicted and reference values were subjected to a simple analysis of variance to determine variation within and across samples. In Exp. 1, mohair base was related to NIR spectra with R2 = .46 and standard error of calibration (SEC) = 2.84%. In Exp. 2, similar repeatability errors for mohair base could be obtained for both reference- and NIRS-derived values. Fiber diameter and medullated fibers were poorly related to NIR spectra. When samples were scanned using the transport mechanism (Exp. 3), R2 and SEC were .82 and 1.19% for mohair base and .93 and .98 microm for fiber diameter, respectively. The CV for mohair base and diameter were 1.0 and 1.4%, whereas those for predicted mohair base and diameter were 1.4 and 3.4%, respectively. The increased variation within samples for predicted values represents sampling error and lack of fit between NIRS and the laboratory determined values. When the samples from Exp. 1 and 2 were rescanned with the NIRS transport (Exp. 4), R2 and SEC were .79 and 2.03% for mohair base and .52 and 3.49 microm for fiber diameter. The fiber optic probe would facilitate real-time analysis on the shearing floor, but our data indicate that the spectral limitations so far are too severe. A large sample device such as the transport gave excellent results for predicting mohair base and fiber diameter.     

长毛兔采毛方式的研究

为了探讨一种取代传统采毛方式－刀剪、手拔的先进技术,我们从法国引进了Ｌａｇｏｄｅｎｄｒｏｎ５００ｋｇ在本所试验兔场及固镇、阜阳兔场进行了试验及推广。结果表明：采毛方式对兔毛产量、质量均有不同程度的影响,刀剪毛对兔毛产量、质量的影响不大;两物手拔毛以后,兔毛产量、粗毛率分别提高９．６５％和２３．１１％;两次使用Ｌａｇｏｄｅｎｄｒｏｎ脱毛以后,兔毛产量、粗毛率分别提高８．４９％和１８．７０％。而且,Ｌ     

安哥拉山羊与本地山羊杂交试验

利用安哥拉山羊与当地土种山羊进行杂交改良，产绒量比本地羊增加两倍以上，有髓毛减少，绒毛增多。杂种羊具有耐粗饲、抗病力强，生长发育相对快等杂种优势。试验组比对照组成活率提高4．16个百分点，繁活率提高4．44个百分点。     

生长毛兔复合添加剂配方筛选试验

选择年龄相近 ,健康无病 ,体重约 1kg的珍珠系长毛兔 1 0 0只 ,根据体重、性别 ,按组间相似的原则分为 4组 ,每组 2 5只 ,A、B、C 3组为试验组 ,分别添加 1 ,2 ,3号复合添加剂 ,D组为对照组 ,添加市售微量元素、多维素添加剂 ,蛋氨酸。试验各组基础日粮完全相同。60d的饲养试验结果表明 ,对照组的发病率显著高于试验组 ,而成活率则低于各试验组。B、C两组的平均增重显著高于对照组 (P <0 0 5 ) ;3个试验组相比 ,B、C组比A组增重分别提高1 0 34%和 1 4 94% ,差异显著 (P <0 0 5 ) ,而B、C两组间增重差异不显著 (P >0 0 5 )。     

长毛兔微卫星标记初步分析

为在长毛兔群体中实施标记辅助选择,对200只长毛兔的sat13、sol33、sat4、so1444个微卫星位点进行了检测。结果表明:这4个微卫星位点都具有高度的多态性,sat4位点杂合度(H)和多态信息含量(PIC)最高,分别为0.8920与0.8790;sat13和so144位点等位基因数为7个,而sat4和so133位点分别有10个等位基因。     

粗纤维水平及品质对家兔的营养作用

粗纤维对家兔的营养作用可以概括为两个方面 :一是经家兔盲肠内的微生物发酵分解为挥发性脂肪酸 (VFA)以提供能量 ;二是维持家兔的正常消化生理。许多研究证明 ,家兔对粗纤维的消化并不十分有效 ,且明显低于马、猪和反刍动物。美国NRC( 1 977)公布家兔、牛、马、猪、豚鼠对粗纤维的消化率分别为 1 4%、44%、41 %、2 2 %和 33%。Cheeke( 1 987)解释了其中的主要原因 :家兔的肠道肌肉运动将大颗粒 (主要是纤维性组分 )挤入结肠 ,形成硬粪然后排出体外 ;同时以逆行蠕动将小颗粒 (主要是非纤维组分 )送入盲肠发酵 ,形成软粪 ,而家兔日粮中纤…     

浙系长毛兔品种选育研究

浙系长毛兔系采用多品种杂交选育,并经种群选择、继代选育、群选群育、系统培育等技术,结合良种兔人工授精配种繁殖等措施,经4个世代选育,形成拥有嵊州系、镇海系、平阳系三个品系的浙系长毛兔新品种,并于2010年7月通过了国家畜禽遗传资源委员会的品种审定。研究表明:浙系长毛兔具有体型大、产毛量高、兔毛品质优、适应性强等优良特性,遗传性能稳定。目前,浙系长毛兔已在国内20多个省市、自治区中试应用300多万只,并为河南、四川、重庆等地的长毛兔新品系选育提供了育种素材,为我国长毛兔产业的提升和可持续发展做出了重要贡献。     

Techniques and success of embryo transfers in Angora goats

Thirty-five mixed-age Angora does were subjected to superovulation and oestrous synchronization and of the 34 which were subsequently entire mated, 33 were subjected to surgical egg recovery approximately five days after oestrus. These 33 donors averaged 8.8 ovulations and 2.5 large (>5 mm) follicles. All corpora lutea in six donors were undergoing premature regression. The average donor egg recovery rate, egg fertilization rate and percent of eggs transferable was 82, 87 and 81%, respectively, giving 6.8 eggs, 6.0 embryos and 5.5 transferable embryos per donor. Egg recovery was reduced dramatically when premature regressing corpora lutea were present. Recipient feral does were synchronized and 183 embryos transferred surgically to 133 recipients.

Eighty-eight (66%) of the recipients kidded producing 118 kids (64% embryo survival). The 35 potential donors produced 36 kids from their natural mating which occurred shortly after surgery. Thus the donors produced a total of 154 kids from embryo transfer and natural mating, an average of 4.4 kids/doe/breeding season. This rate of reproduction is four to five times faster than normal and confirms that the technique achieves its objective of rapidly increasing the number of offspring from selected animals.     

长毛兔选育测定模式研究

选用德系安哥拉兔为试验材料，研究设计了一套适用于基础育种场细毛型长毛兔选育测定的模式。该模式主要分产毛测定和繁殖测定两大阶段。通过模式在种兔场的实际应用，结果表明：种兔选育测定实行模式化，可最大限度地减少外界因素对种兔选育的干扰和影响。提高种兔选育效率，增强选育测定结果的可比性，并可促进种兔场管理水平及经济效益的提高。     

Conduction velocities and myelinated fiber diameter spectra of the infraorbital and palpebral nerves of the dog

Maximum conduction velocities of compound-action potentials of the infraorbital (ION) and palpebral (PN) nerves were determined by averaging potentials evoked and recorded through subcutaneous needle electrodes. The specificity of the stimulating and recording sites was verified by recording before and after cutting the nerves. Conduction times for orthodromically and antidromically conducted potentials of the ION were essentially the same. The unipolarly recorded antidromic compound-action potentials of the ION were of higher peak-to-peak amplitude and were more reliably recorded than were the bipolarly recorded orthodromic action potentials. Areas of cutaneous innervation were not found for the PN. Neuromuscular blockade eliminated the volume-conducted muscle action potentials that were recorded after PN stimulation, allowing triphasic nerve action potentials to be recorded unobscured. Mean conduction velocities were: ION = 83.9 +/- 3.5 m/s; PN = 56.4 +/- 2.8 m/s. Distributions of the external diameters of myelinated fibers within the ION and the PN were determined.     

Techniques and success of embryo transfers in Angora goats

Thirty-five mixed-age Angora does were subjected to superovulation and oestrous synchronization and of the 34 which were subsequently entire mated, 33 were subjected to surgical egg recovery approximately five days after oestrus. These 33 donors averaged 8.8 ovulations and 2.5 large (>5 mm) follicles. All corpora lutea in six donors were undergoing premature regression. The average donor egg recovery rate, egg fertilization rate and percent of eggs transferable was 82,87 and 81%, respectively, giving 6.8 eggs, 6.0 embryos and 5.5 transferable embryos per donor. Egg recovery was reduced dramatically when premature regressing corpora lutea were present. Recipient feral does were synchronized and 183 embryos transferred surgically to 133 recipients. Eighty-eight (66%) of the recipients kidded producing 118 kids (64% embryo survival). The 35 potential donors produced 36 kids from their natural mating which occurred shortly after surgery. Thus the donors produced a total of 154 kids from embryo transfer and natural mating, an average of 4.4 kids/doe/breeding season. This rate of reproduction is four to five times faster than normal and confirms that the technique achieves its objective of rapidly increasing the number of offspring from selected animals.     

Lily of the valley poisoning in an Angora goat

Extract

Madam: — We recently treated a goat poisoned by the lily of the valley tree. On Thursday the 30th of December, an adult Angora buck was presented with the following symptoms: projectile vomiting, ataxia, depression, excessive salivation, toxic mucous membranes, weak ruminal movements and a subnormal temperature. The vomiting was spectacular and included numerous leaves of one species of plant.     

Clinicopathologic diagnosis of cutaneous toxoplasmosis in an Angora cat

This report deals with a case of cutaneous toxoplasmosis in a 2 year-old female Angora cat. Cutaneous lesions were characterized by prescapular ulcers and hyperemic nodules in the skin of the inguinal and dorsosacral regions. A skin biopsy sample was collected from the lesioned area and processed for histopathologic examination and immunoperoxidase test using Toxoplasma gondii and Neospora caninum specific antibodies. Toxoplasma gondii immunopositive reactions were detected in keratinocytes and dermal macrophages while no immunoreactivity was detected for N. caninum. The case of cutaneous toxoplasmosis was further confirmed by PCR analysis using T. gondii B1 gene-specific primers. In conclusion, we report the first case of cutaneous toxoplasmosis in Angora cats.