Toxicity of Jatropha curcas in sheep and goats

The sequential development of the clinical signs and lesions in the organs of desert sheep and Nubian goats dosed with Jatropha curcas seeds at 0.05, 0.5 and 1 g/kg/day was studied. Diarrhoea, reduced water consumption, dehydration, sunken eyes, inappetence and loss in condition were the important signs of J curcas poisoning in sheep and goats. The main pathological changes were haemorrhage in the rumen, reticulum, lungs, kidneys and heart, catarrhal and/or haemorrhagic enteritis, hepatic fatty change, pulmonary congestion and oedema and straw-coloured fluid in serous cavities. An increase in the concentrations of AST, ammonia, potassium and sodium and a decrease in total protein and calcium were detected in the serum. Haematological changes were haemoconcentration and leucocytosis.     

Measurement of glucocorticoid metabolite concentrations in faeces of domestic livestock

After 14C-labelled cortisol infusion in ponies and pigs, faecal samples were collected. Extraction of 0.5 g faeces with 5 ml 80-90% methanol yielded the highest radioactivity in the supernatant. Most of the metabolites were ether soluble. After high performance liquid chromatography (HPLC), the presence of immunoreactive metabolites was demonstrated by measuring each HPLC fraction using enzyme immunoassays for cortisol, corticosterone and 11-oxoaetiocholanolone. Only the assay for 11-oxoaetiocholanolone revealed peaks with co-eluting radioactivity. For biological validation of the test system, adrenocorticotrophic hormone (ACTH) and dexamethasone were injected intravenously successively in both species (n = 6). Cortisol concentration in blood and the 11-oxoaetiocholanolone immunoreactive substances in faeces were determined. In horse faeces, basal values of 2.3-35.2 nmol/kg were measured. After ACTH administration, an increase (more than 200% above basal values) of these metabolites was seen about 1 day after ACTH administration. After dexamethasone injection the levels decreased, reaching minimum concentrations 2 days after administration. In pigs, an increase in these metabolites was measured in only three animals after ACTH; dexamethasone did not cause a decrease. The stability of the samples after defecation was tested by storing samples from cows, horses and pigs at room temperature. It was shown that there was a significant increase in the concentration of measured cortisol metabolites in bovine, equine and porcine faeces after storage for 1 h, 4 h and 24 h, respectively. In frozen samples this effect was diminished after thawing samples at 40 degrees C; thawing the samples at 95 degrees C prevented an increase in immunoreactive substances.     

Toxicity of flufenamic acid in the cat

Twelve cats were treated with dosages of flufenamic acid varying from 80 to 5 mg/kg daily. Cats on high doses showed clinical signs compatible with phenol toxicity, while those on lower dosages were slightly depressed and inappetant. It was concluded that flufenamic acid should not be used in this species.     

Pathology of AA amyloidosis in domestic sheep and goats

We describe the main pathologic changes in small ruminants affected by AA amyloidosis, together with the partial sequence of the protein involved. Twenty-one sheep and one goat were selected for presenting macroscopic kidney lesions compatible with systemic amyloidosis. Available tissue samples were studied by histologic, immunopathologic, and ultrastructural means. Renal lesions were characterized grossly by pale cortical surfaces with scattered, miliary, whitish-yellow foci and on cut cortical surfaces by straight, whitish-yellow striations. Gangrenous pneumonia was observed in 16 out of 21 affected sheep (76.2%), although other chronic inflammations were also observed. Amyloid was detected in all grossly affected kidneys using Congo red staining, lesions being most remarkable in glomeruli, affecting 95.5% of animals studied. Congophilic deposits were also observed in intertubular interstitium (68.2%) and medulla (57.1%). All amyloid-affected animals presented proximal convoluted tubule lesions, mostly characterized by an increase in diameter and by hyaline granular degeneration that were responsible for the macroscopic appearance of the kidney. Histologically, amyloid was also seen in blood vessels, spleen, liver, lymph nodes, gastrointestinal tract, and adrenal glands. All amyloid deposits demonstrated greenish-yellow birefringence with polarized light, and the antisera prepared against goat amyloid extracts specifically reacted with birefringent congophilic deposits of both sheep and goats. Ultrastructurally, these deposits were formed by masses of straight, nonbranching fibrils located predominantly in the basement membranes of glomerular capillaries and in the mesangium. Partial sequence of the protein in sheep and goats indicated a high degree of homology with the previously reported sequence of sheep Serum Amyloid A.     

Organophosphorus compounds. I. Toxicity in domestic animals

Organophosphorus compounds with various aspects of their modes of action, toxicity and antidotal treatment have been briefly reviewed. Their clinical, pathological and biochemical effects on different species of domestic animals are also described.     

Mycoplasma conjunctivae infection is self-maintained in the Swiss domestic sheep population

Bacteriological and serological investigations were performed to assess whether the domestic sheep population is a reservoir of Mycoplasma conjunctivae in Switzerland. Among a sample of 69 sheep showing clinical signs of infectious keratoconjunctivitis (IKC) in three Swiss cantons, M. conjunctivae was identified 53 times (76.8%). A commercially prepared indirect ELISA was used to detect M. conjunctivae antibodies in 674 sera of adult sheep. We analysed a stratified random sample of 123 sheep herds from 25 out of the 26 Swiss cantons. At least one positive animal was detected in 89.4% of the herds. In positive herds (n=110), 57.1% of the individual animals tested positive. To assess the importance of sheep's age in the spread of M. conjunctivae, 209 sera of adult sheep and 93 lamb sera among eight sheep herds were analysed using the indirect ELISA. Seroprevalence in 2-6-month-old lambs was 50.5%, indicating that the IKC agent is spread in sheep flocks during raising. Lambs experimentally infected with M. conjunctivae carried the agent for 8 and 23 weeks, respectively, depending on the strain used for challenge. We conclude that the M. conjunctivae-infection is endemic and self-maintained in the domestic sheep population in Switzerland.     

Chiral behaviour of the metabolite albendazole sulphoxide in sheep, goats and cattle

Three sheep, three goats and three cattle were dosed orally with 5.0, 7.5 and 10 mg albendazole kg-1 bodyweight, respectively. Blood samples were taken at intervals for 48 hours after administration. The enantiomeric ratio of the metabolite albendazole sulphoxide (SO.ABZ) was determined by liquid chromatography on chiral stationary phases. At To, the plasma concentration ratio (+)SO.ABZ/(-)SO.ABZ was estimated at 3.0 in sheep, 1.5 in goats and 4.0 in cattle. The proportion of the (+) enantiomer then increased linearly as a function of time during the course of the kinetics. In comparison to the area under the curve for total SO.ABZ, the (+) enantiomer represented 86 per cent in sheep, 80 per cent in goats and 91 per cent in cattle. The specific behaviour of the two enantiomers is probably the result of the enantioselectivity of the flavine adenosine dinucleotide and cytochrome P450 dependent enzymatic systems which are involved in the sulphoxidation and the sulphonation of ABZ.     

绵羊染色体研究的回顾与展望

对国内外绵羊染色体的研究方法及现状进行了综述。绵羊二倍体细胞染色体数2n=54；1976年Reading会议和1989年国际染色体标准化会议上，G-和R-带标准化核型的建立，为研究绵羊各种染色体畸变与染色体的准确识别提供了可靠的方法。高分辨显带方法的应用，为更准确地识别染色体，基因的物理定位，以及从细胞水平揭示基因的活动等提供了更直接的途径，也必将在以后基因组研究中发挥重要作用；深入研究各种染色体核型及变异与生产性能之间的关系，为绵羊育种和生产提供依据。     

Pharmacokinetics and sedative effects of intramuscular medetomidine in domestic sheep

Intramuscular (i.m.) administration of medetomidine (MED) may avoid the severe pressor effects caused by peripheral actions of MED associated with intravenous (i.v.) dosing. The purpose of this study was to determine the pharmacokinetics, the time course of sedation and occurence of hypoxaemia after i.m. administration of MED in domestic sheep. The MED was injected i.m. at a dose of 30 micro g/kg in nine domestic sheep. Blood was sampled at 0, 5, 10, 20, 30, 40, 60, 120, 180, 240, 360 and 600 min after MED. Sedation was assessed and arterial blood samples were taken before and 35 min after MED application. Mean (SD) pharmacokinetic parameters of i.m. MED were: absorption half-life: 13.2 (7.5) min; terminal half-life: 32.7 (14.9) min; time to peak concentration: 29.2 (8.9) min; peak concentration: 4.98 (1.89) ng/mL; volume of distribution: 3.9 (2.4) l/kg; total body clearance: 81.0 (21.5) mL/(min kg). Peak sedation occurred between 30 and 40 min after injection of MED. The degree of sedation correlated with individual plasma concentrations (rS: 0.926). One animal became hypoxaemic (PaO2 = 54.1 mmHg).     

Models to capture the potential for disease transmission in domestic sheep flocks

Successful control of livestock diseases requires an understanding of how they spread amongst animals and between premises. Mathematical models can offer important insight into the dynamics of disease, especially when built upon experimental and/or field data. Here the dynamics of a range of epidemiological models are explored in order to determine which models perform best in capturing real-world heterogeneities at sufficient resolution. Individual based network models are considered together with one- and two-class compartmental models, for which the final epidemic size is calculated as a function of the probability of disease transmission occurring during a given physical contact between two individuals. For numerical results the special cases of a viral disease with a fast recovery rate (foot-and-mouth disease) and a bacterial disease with a slow recovery rate (brucellosis) amongst sheep are considered. Quantitative results from observational studies of physical contact amongst domestic sheep are applied and results from the differently structured flocks (ewes with newborn lambs, ewes with nearly weaned lambs and ewes only) compared. These indicate that the breeding cycle leads to significant changes in the expected basic reproduction ratio of diseases. The observed heterogeneity of contacts amongst animals is best captured by full network simulations, although simple compartmental models describe the key features of an outbreak but, as expected, often overestimate the speed of an outbreak. Here the weights of contacts are heterogeneous, with many low weight links. However, due to the well-connected nature of the networks, this has little effect and differences between models remain small. These results indicate that simple compartmental models can be a useful tool for modelling real-world flocks; their applicability will be greater still for more homogeneously mixed livestock, which could be promoted by higher intensity farming practices.     

雄性马可·波罗盘羊与家绵羊头骨形态特征比较

盘羊是中国境内唯一的野生绵羊,在中国境内有6个亚种,马可·波罗盘羊是盘羊体型最大的亚种,主要分布在中国、塔吉克斯坦、巴基斯坦、阿富汗和吉尔吉斯坦5国边境。本试验搜集雄性马可·波罗盘羊头骨18例(年龄为5~10岁)进行形态解剖,并与家绵羊进行比较。结果表明:(1)盘羊的头骨形态特征与家绵羊十分相似,但盘羊头骨大,尤其角大螺旋呈S型,头骨狭长,吻部长而扁平,鼻孔较大,前颌骨平坦且与鼻骨相连处稍凹陷,眼窝面积大而深,牙齿两侧的上颌骨与颚骨连接处以及枕骨与基蝶骨完全愈合;而家绵羊头骨较短,鼻骨隆起,吻部短小,眼窝不明显,牙齿两侧的上颌骨与颚骨连接处以及枕骨与基蝶骨未愈合且有明显的凸起。(2)盘羊5岁后,头骨的上颊齿列基长、眼窝长、乳突间距、眶间距、颧宽、枕颅高、枕髁宽、脑颅最大宽、角基最窄、最小角尖距和最大角尖距等11项指标已稳定,头骨形态基本固定;但头骨眶下孔距、角基周长、角基长径、角基短径和角外侧长等随着年龄的增长而显著增大(P0.05),上颌臼齿外宽和角尖距与年龄存在极显著正相关(P0.01)。(3)对盘羊23项测量指标间的相关性进行分析,发现盘羊头骨不是趋同生长。与家绵羊相比,除听泡长外,其余21项测量指标间存在极显著性差异(P0.01),因此两者容易辨别。     

Fatal Pasteurella haemolytica pneumonia in bighorn sheep after direct contact with clinically normal domestic sheep

Six Rocky Mountain bighorn sheep were raised in captivity from birth (n = 5) or taken from the wild as a lamb (n = 1). After the bighorn sheep were in captivity for over a year, 6 clinically normal domestic sheep were placed on the 2 ha of pasture on which the bighorn sheep were kept. Nasal swab specimens were obtained from all sheep at the time the domestic sheep were introduced. Pasteurella haemolytica was isolated from swab specimens obtained from 4 of 6 domestic sheep, but not from specimens obtained from the bighorn sheep. All 6 bighorn sheep died of acute hemorrhagic pneumonia after exposure to domestic sheep. Death in the bighorn sheep occurred on days 4, 27, 27, 29, 36, or 71 after initial exposure to domestic sheep. Pasteurella haemolytica was isolated from respiratory tract tissue specimens of all bighorn sheep at the time of death. None of the domestic sheep were clinically ill during the study. At the end of the study, 3 of 6 domestic sheep were euthanatized, and at necropsy, P haemolytica was isolated from 2 of them. The most common serotypes in bighorn and domestic sheep were P haemolytica T-3 and A-2. Other serotypes isolated included P haemolytica A-1, A-9, and A-11 in bighorn sheep and A-1 in domestic sheep. On the basis of results of this study and of other reports, domestic sheep and bighorn sheep should not be managed in proximity to each other because of the potential fatal consequences in bighorn sheep.     

国内几个绵羊品种转铁蛋白多态性研究

试验采用聚丙烯酰胺凝胶水平板电泳,检测了蒙古羊、小尾寒羊、新疆肥臀羊和兰州大尾羊转铁蛋白的多态性。结果发现,蒙古羊中存在TfA、TfB、TfC、TfD、TfG和TfL6个复等位基因,TfA和TfB为优势基因,频率分别为0.3500和0.2750;小尾寒羊中存在TfA、TfB和TfC3个复等位基因,频率分别为0.3210,0.3930和0.2860;新疆肥臀羊存在TfA、TfB、TfC和TfD4个复等位基因,频率分别为0.0750,0.6750,0.2250和0.0250;兰州大尾羊中存在TfA、TfB、TfC、TfD、TfG和TfL和TfM7个复等位基因,其中TfB和TfC为优势基因,频率分别为0.4845和0.3528。蒙古羊、小尾寒羊、新疆肥臀羊和兰州大尾羊转铁蛋白基因平均杂合度分别为0.7338,0.6607,0.4875,0.6338。     

Susceptibility of Rocky Mountain bighorn sheep and domestic sheep to pneumonia induced by bighorn and domestic livestock strains of Pasteurella haemolytica.

Bighorn sheep were inoculated intratracheally with suspensions of nonhemolytic Pasteurella haemolytica biotype T (10(12) organisms) unique to wild bighorns, with beta-hemolytic P. haemolytica biotype T (10(12) organisms) isolated from clinically normal domestic sheep or intradermally with half a dose of a cattle vaccine containing P. haemolytica biotype A (10(5) organisms). The bighorn strain caused lobar necrotizing bronchopneumonia whereas both domestic livestock strains precipitated fatal septicemia and fibrinous bronchopneumonia. The serotypes given were T3, T4, T15 and A1 and these were recovered from lung lesions and other organs. In three trials, domestic sheep were inoculated intratracheally with suspensions of bighorn sheep pneumonic lungs, and two concentrations of the P. haemolytica bighorn strain (10(4) and 10(12) organisms). One of these sheep was inoculated intrabronchially. The domestic sheep experienced a transient fever and elevated white blood cell counts. After six days, none of the sheep had lung lesions and inoculated organisms could not be recovered. It is suggested that bighorn sheep are very susceptible to P. haemolytica from domestic livestock and should not be allowed in contact with sheep or cattle.