Immune responses of cattle to biochemically modified antigens from the midgut of the cattle tick, Boophilus microplus

Treatment of membrane antigens of the midgut (GM) of the cattle tick, Boophilus microplus with sodium metaperiodate (periodate), pronase and lipase significantly inhibited the reactivity of the GM with antibodies in the sera of 57 cattle vaccinated with GM. Treatment of GM with periodate only removed the correlation between antibody reactivity of sera and protection against infestation with ticks. A monoclonal antibody (MoAb QU13), which recognises protective antigens solubilized from GM (Lee + Opdebeeck 1991), did not react with GM treated with periodate. Cattle vaccinated with GM extracts were significantly protected against infestation with cattle ticks (P less than 0.05), whereas cattle vaccinated with either GM extracts treated with periodate or with antigens precipitated from GM extracts with MoAb QU13 and also treated with periodate, were not protected against infestation. These studies provide preliminary evidence that protective antigens in the tick midgut membrane either are carbohydrate or are dependent on carbohydrate for their specificity.     

Susceptibility of N''Dama and Boran cattle to tsetse-transmitted primary and rechallenge infections with a homologous serodeme of Trypanosoma congolense

Eight trypanotolerant N'Dama cattle controlled an infection of Trypanosoma congolense ILNat 3.1 transmitted by Glossina morsitans centralis, more efficiently than a group of similarly infected trypanosusceptible Boran cattle. All eight N'Damas maintained their PCV above 15% throughout the primary infection whereas the PCV of six of the eight Borans dropped below 15%; these latter animals were treated with diminazene aceturate to prevent possible death. Lymphocyte, neutrophil and platelet counts also decreased in the Boran during the primary infection. In contrast, a lymphocytosis was observed in the N'Dama; and although the neutrophil and platelet counts decreased, the drop was less severe than in the Boran. Two years after the primary infection and immediately prior to a homologous rechallenge infection, all eight N'Damas had neutralizing anti-metacyclic trypanosome variant-specific antibodies present in their sera compared to five of the eight Borans. Following the homologous rechallenge infection the eight N'Damas became parasitaemic but there were no alterations in their erythrocyte or leukocyte counts. The Borans became highly parasitaemic and developed severe, chronic anaemia and leukopaenia. Thus, the trypanotolerant N'Damas controlled a primary infection of T. congolense more efficiently than trypanosusceptible Boran cattle and eliminated a homologous rechallenge infection without the pathology associated with the disease.     

河南省南阳地区黄牛狂犬病病毒的分离和鉴定

应用鼠脑传代,从具有神经症状的病牛脑组织中分离获得5株病毒,经电子显微镜观察呈典型弹状病毒样粒子。用抗狂犬病毒CVS(狂大病毒1型代表株)免疫血清作ELISA检测及小鼠中和试验,证明分离株病毒为狂大病毒。用狂犬病相关病毒Lagos bat(狂犬病毒2型)、Mokola(狂犬病毒3型)和Duvenhage(狂犬病毒4型)免疫血清对分离株病毒作交叉中和试验,结果发现分离株病毒与Duvenhage有较密切的抗原联系,而与Lagos bat及Mokola病毒没有抗原联系。用自制狂犬病毒“核蛋白”单克隆抗体作夹心间接ELISA检测分离株病毒的感染鼠脑均呈阳性反应,5株病毒与CVS及其互相之间没有明显差异。结论认为,由河南省黄牛分离的病毒为狂犬病毒。     

Improvement in Smallholder Farmer Knowledge of Cattle Production,Health and Biosecurity in Southern Cambodia between 2008 and 2010

Farmer knowledge surveys were conducted in 2008 and 2010 in Cambodia to evaluate the impact of a research project studying interventions that can improve cattle production and health, including biosecurity and practices relating to risks of transmission of transboundary diseases. The project hypothesis is that by increasing the value of smallholder‐owned large ruminants through nutritional interventions and improved marketing, knowledge‐based interventions including risk management for infectious diseases such as foot‐and‐mouth disease (FMD) can be implemented into a more sustainable pathway for rural development. Between 2008 and 2010, significant improvements in farmer knowledge and attitudes were recorded in three villages in three provinces of southern Cambodia. This was achieved through participatory ‘applied field research’, ‘on the job’ training plus ‘formal’ training programmes. No cases of FMD were recorded during the study period in the ‘high‐intervention’ (HI) villages despite the common occurrence of the disease in a nearby ‘low‐intervention’ and many other villages in the three provinces. Whilst it is likely that protection of these villages from FMD infection was from increasing the herd immunity by vaccination, it could also have been partly because of a decrease in risk behaviours by farmers as a result of their increasing knowledge of biosecurity. The research indicates that smallholder farmers are motivated by nutritional interventions that improve the value of their cattle ‘bank’ and offer better marketing opportunities. This provides a more receptive environment for introduction of disease risk management for infectious and other production limiting diseases, best implemented for smallholder farmers in Cambodia by intensive training programmes. In lieu of a widespread public awareness programme to deliver mass education of smallholder farmers in disease prevention and biosecurity, livestock development projects in South‐East Asia should be encouraged to include training in disease risk management as an important intervention if the current momentum for trade in large ruminant livestock and large ruminant meat is to continue to progress and contribute to addressing global food security concerns.     

Slaughtered aged cattle might be one dietary source exhibiting amyloid enhancing factor activity

It has been shown that experimental murine AA amyloidosis can be enhanced by dietary ingestion of amyloid fibrils, and it is known that systemic AA amyloidosis occasionally develops in aged cattle. In this study, we examined amyloid deposits in renal and muscular tissues simultaneously obtained from slaughtered aged cattle; from both tissues when affected, amyloid-enhancing activity was also investigated. On histopathology, renal amyloid deposition was seen in nine of the 293 cattle with no history of disease, and minute amyloid deposition in muscular tissue was detectable in one of these nine. All these amyloid deposits were immunohistochemically demonstrated to be AA. Extracts, which might contain amyloid fibril fractions, were isolated from renal and muscular tissues in five of these nine cattle. On SDS-PAGE and Western blot analysis, protein bands immunoreactive to anti-AA serum were detected in the kidney fractions obtained from four of the five latter cattle, but no bands were seen in the muscle fractions of any of the five cattle. Amyloid fibril fractions from two cattle were intravenously injected into group of seven experimentally designed mice for induction of AA amyloidosis. All seven mice injected with kidney fraction developed severe AA amyloidosis, whereas only one of the seven mice given muscle fraction showed slight amyloid deposition in the spleen. These data suggest that food products made from aged cattle possess amyloid-enhancing potential.     

贵州思南黄牛线粒体DNA D-loop区全序列多态性分析

为了解贵州思南黄牛的遗传多样性及遗传背景,我们测定了21个个体线粒体DNA D-loop区序列。检测到8种单倍型,4种为普通牛血统的单倍型,4种为瘤牛血统的单倍型,表明思南黄牛同时受普通牛和瘤牛的影响。这对于思南黄牛的保种及持续利用有着重要的理论指导意义。     

Chromosomal evolution in bovids: a comparison of cattle,sheep and goat G- and R-banded chromosomes and cytogenetic divergences among cattle,goat and river buffalo sex chromosomes

A G- and R-banding comparison of cattle (Bos taurus, 2n=60), goat (Capra hircus, 2n=60) and sheep (Ovis aries, 2n=54) chromosomes at the 450 band level was made. The study revealed a large number of banding homologies among the autosomes of the three species and resolved some ambiguities in arranging some of their small disputed acrocentrics by direct and indirect comparisons with some bovid marker chromosomes. A loss of the subcentromeric G-positive band in sheep chromosome 2q was observed when the G-banding patterns of sheep 2q and homologous cattle and goat chromosome 2 were compared. The chromosomal divergences among cattle, goat and river buffalo (Bubalus bubalis, 2n=50) sex chromosomes are shown to have occurred by pericentric and paracentric inversions with a loss (or acquisition) of constitutive heterochromatin.     

Response of bovine intra-ocular muscles to transmural stimulation in the presence of various prostaglandins

Effects of prostaglandins (PGs) E1, E2 and F2 alpha on the electrically stimulated and non-stimulated smooth muscles of bovine intra-ocular tissues were investigated in vitro. PGs E1, E2 and F2 alpha contracted the sphincter and these contractions were not antagonized by either cholinergic or adrenergic blocking agents. PGF2 alpha was much weaker than PGE1 or PGE2. PGs in high concentrations produced an irreversible contracture of the sphincter muscle. In contrast, the dilator muscle contracted with PGF2 alpha, but not PGE1 or PGE2. The ciliary muscle did not respond to these PGs or to indomethacin. Electrical field stimulation with short pulses produced excitation of the intrinsic nerves. The responses produced were not altered in amplitude by the application of any dose of PGs or indomethacin, although indomethacin did lower the tone of the sphincter. PGs did not influence the amplitude of the acetylcholine-induced responses of the intra-ocular muscles. These results indicate that in each of the bovine intra-ocular muscles, PGs play a minor role in neuromuscular transmission both prejunctionally and postjunctionally. Thus, PG-induced contractions of the bovine intra-ocular muscles are considered to occur by a direct action on the muscle rather than on the nerves.     

Vaccination of cattle with Brucella abortus strain 19 administered by differing routes and doses

As a result of brucellosis control problems in large Florida dairy herds the use of Brucella abortus strain 19 vaccination has been re-examined. Cattle were vaccinated with different doses of Brucella abortus strain 19 administered by different routes. On the whole, the route of administration was found to have little influence on the efficacy of the vaccine, although the efficacy of vaccine administered orally was difficult to assess. The reduced doses given subcutaneously was selected as the preferred method for adult cattle vaccination.     

液-液萃取法从湿法磷酸中脱氟制饲料磷酸氢钙

发现三辛胺(TOA)萃取氟时,在氯仿(CLF)、二氯乙烷稀释剂中有很强的溶剂效应,可使分配比D_F增大约8.8倍,分离系数β_(F/P_2O_5)增大约66倍。研究了该体系的萃取行为和性质,考察了各种因素对萃取性能的影响,从而确定了分离的最佳工艺条件:298K;平衡时间约120s;溶剂配比为TOA∶CLF∶煤油=1∶2∶2(v/v);相比为1;三级逆流萃取。反萃取条件为:313K;碱液浓度1～2kmol/m~3;单级反萃取。脱氟磷酸与Ca(OH)_2中和反应4小时,产品磷酸氢钙(CaHPO_4·2H_2O)中F<0.15%。