藏系绵羊钼诱导铜缺乏的研究

自2000年以来,青海省乌兰地区藏绵羊出现以异食、消瘦和贫血为特征的疾病。经分析该地区土壤、牧草和动物的矿物质元素含量,发现在患病区,土壤钼含量为（4.63±1.51）μg/g,牧草为（4.89±1.79）μg/g,极显著高于正常地区。患病动物血液平均铜含量为（0.23±0.07）μg/g,被毛铜平均含量为（3.27±0.71）μg/g,而正常区的动物为（0.97±0.23）μg/g和（6.78±1.57）μg/g,差异极显著;患病动物血液铜最高值为0.53μg/g,血液铜最低值为0.031μg/g。而正常地区藏绵羊血液铜含量最高值为1.33μg/g,血液铜最低值为0.83μg/g。同时患病动物血清铜蓝蛋白显著低于正常动物,并且有小红细胞贫血。结果表明,藏绵羊以异食、消瘦和贫血为特征的营养代谢疾病为钼诱导的次级铜缺乏。     

锌、铜对实验性钼中毒绵羊肝脏、肾脏中钼含量的影响

小尾寒羊20只,随机分为5组,分别口服钼、铜和锌(mg/kg),Ⅰ组30mg/kg钼、Ⅱ组30mg/kg钼+15mg/kg铜、Ⅲ组30mg/kg钼+15mg/kg锌、Ⅳ组30mg/kg钼+15mg/kg铜+15mg/kg锌,Ⅴ组去离子水。试验90d期满,采取肝脏和肾脏,硫酸-高氯酸消化,原子吸收法测定钼、锌、铜含量,结果显示,Ⅰ组肝脏钼含量与第Ⅱ、Ⅲ、Ⅳ、Ⅴ组差异极显著(P<0.01),Ⅱ、Ⅲ组与Ⅳ、Ⅴ组差异极显著(P<0.01);Ⅳ组肝脏铜含量与Ⅰ、Ⅲ、Ⅴ组差异极显著(P<0.01),与Ⅱ组差异显著(P<0.05),Ⅱ组肝铜含量与Ⅰ、Ⅲ、Ⅴ组差异极显著(P<0.01);组间肝脏锌含量均差异极显著(P<0.01)。Ⅰ、Ⅲ组肾钼含量显著高于Ⅱ、Ⅳ、Ⅴ组(P<0.01);Ⅱ与Ⅳ、Ⅴ组差异极显著(P<0.01);肾铜含量Ⅲ组与Ⅰ组差异极显著(P<0.01);Ⅱ、Ⅲ、Ⅳ组与Ⅰ、Ⅴ组差异极显著(P<0.01);各组肾脏锌含量差异均极显著(P<0.01)。结果表明,30mg的钼可使肝脏钼含量显著增加(P<0.01),锌、铜含量降低。锌对肝脏钼有很好的颉抗作用,铜、锌有效地降低了钼在组织中的蓄积。     

陕南贫困地区应用微生态制剂提高肉羊养殖经济效益研究

本文主要从肉羊养殖角度来对陕南贫困地区应用微生态制剂的情况做出分析,希望可以进一步提高肉羊养殖的经济效益。试验选取体重一致的90d肉羊240只,随机分为3组,每组10个重复,每个重复8只羊。试验共设计3种日粮:对照组饲喂未加工的玉米秸秆日粮,试验1组饲喂未加工的青贮玉米秸秆日粮,试验2组饲喂添加EM菌剂发酵后的玉米秸秆。试验共开展2个月。结果发现,采用EM菌剂发酵玉米秸秆饲喂的肉羊体重增加6.71kg/只,增重及盈利均明显高于试验I组及对照组,收益分别提高了16.99元/只和4.87元/只。因此,微生态制剂能提升肉羊养殖的经济效益,可予以推广应用。     

Effects of 2-mercaptoethanol on the solubility of copper and zinc containing proteins in liver samples from normal and chronic copper poisoned sheep

The solubility of Cu and Zn binding proteins was studied in liver samples from clinically healthy and chronic copper poisoned sheep (CCP). Homogenized liver was divided by ultracentrifugation into cytosol and pellet. The cytosol was gelfiltrated, Cu and Zn contents were determined in the eluates as well as in the pellet. Liver homogenate, cytosol and pellet were treated with 2-mercaptoethanol (ME). The resulting clear solutions were fractionated by gel filtration followed by determination of the contents of the two metals in the eluates.In CCP sheep the solubility of Cu containing proteins from the liver homogenate and pellet increased after incubation with ME.The results suggest that in CCP sheep a considerable amount of Cu containing proteins are present in an insoluble form, which to some extent is resolubilized by ME.     

The use of divalent cation chelating agents (EDTA/EGTA) to reduce non-specific serum protein interaction in enzyme immunoassay

An indirect enzyme immunoassay (ELISA) for detection of bovine antibody toBrucella abortus was modified by the addition of divalent chelating agents to the serum diluent. This addition resulted in an increase in specificity from 96.0% in the regular assay to 99.4% in the modified procedure. Of the 15 715 sera initially tested by the indirect ELISA, 691 that had given positive reactions were selected for retesting in the indirect ELISA with EDTA/EGTA added. The buffered plate antigen test (BPAT) correctly identified 98.6% of the samples as negative. The addition of chelating agents did not alter the sensitivity of the indirect ELISA, which correctly classified 609 sera from animals from whichB. abortus had been isolated as positive. The sensitivity of the BPAT was 97.8%.Abbreviations ABTS 2,2-azinobis(3-ethylbenzthiazoline sulphonic acid) - BPAT buffered plate antigen test - EDTA ethylenediaminetetraacetic acid disodium salt - EGTA ethylene glycol-bis(-aminoethyl ether)-N,N,N,N-tetraacetic acid - ELISA enzyme-linked immunosorbent assay - IgG₁ immuno- globulin G₁ - IgM immunoglobulin M - Tris tris(hydroxymethyl)aminomethane     

Listeriosis in sheep. Listeria monocytogenes excretion and immunological state in sheep in flocks with clinical listeriosis.

The excretion of Listeria monocytogenes (Lm) in the faeces and milk, and humoral immunity against Lm, were examined in a sheep flock with outbreaks of listeric encephalitis and in a flock with outbreaks of listeric abortion. The encephalitis flock consisted of 86 ewes and 20 hoggs, the abortion flock of 45 ewes and 3 hoggs, all of them pregnant. Faecal excretion rate in the encephalitis flock varied from about 25 % in the first part of the indoor season to nearly zero 1 month later, to about 30 % 1 month before lambing and about 15 % at lambing. About 15 % of the animals also excreted Lm in the milk. Lm 4 was the dominating serotype.In the abortion flock about 2/3 of the animals excreted Lm in the faeces and 1/3 in the milk at lambing. All the isolates belonged to serotype 1, which also was isolated from grass silage and strawbedding samples.In the encephalitis flock ewes with ≥ 3 foetuses had a higher excretion rate than the remainder, while no such differences were found in the abortion flock.Antibody titres against Lm in sera and whey in the encephalitis flock were of the same order as in the healthy flock described in an earlier publication (Grønstøl 1979), except that the highest titres were found in the hoggs. Serum titres from the abortion flock after lambing were significantly higher than in the encephalitis flock, while whey titres were of the same order.Treatment with 2-mercapto-ethanol reduced the titres substantially in sera from the abortion flock, indicating that the antibodies belonged to the IgM-fraction, while only a slight reduction was seen after similar treatment of the whey.     

Comparison of a novel form of zinc with zinc oxide bolus licensed for prevention of facial eczema,and interaction with copper oxide in sheep

To evaluate a novel elemental zinc bolus compared with a registered positive control zinc oxide bolus and assess serum zinc concentrations following concomitant treatment with a capsule containing copper oxide needles. Forty Romney-cross ewes were randomly allocated in a 2 × 2 factorial design study. On Day 0, 20 ewes received novel boluses containing elemental zinc (Investigational Veterinary Product, IVP) while 20 received a zinc oxide bolus (control; CP). Half the animals in each zinc treatment group (n = 10) were treated with a copper oxide needle capsule [Copasure® - Ewe]. Weekly, from Day −7 to 56, all ewes were assessed for signs of photosensitization, and for 10 ewes from each zinc treatment groups, samples were collected for analysis of serum GGT activity, serum zinc concentrations, faecal zinc concentrations and on Days −7 and 56, liver copper concentrations. Multivariable random-effects models assessed the effects of zinc treatment, copper treatment, treatment interactions and time on all analytes. Regression models examined associations between serum and faecal zinc concentrations and GGT activity. Low spore numbers indicated low Pithomyces chartarum challenge. Serum zinc levels were significantly higher in the IVP than in the CP group [p < 0.0001] and varied by time [p < 0.001] and positively associated with faecal zinc concentration [p < 0.001]. Copper treatment did not affect serum zinc [p = 0.82] or faecal zinc [p = 0.92] concentrations. Liver copper concentrations did not differ between zinc treatment groups on Day −7 [p = 0.6] or Day 56 [p = 0.95]. Only the CP/no copper group had no increase in liver copper concentrations.     

Minimum length of the adaptation and collection period in digestibility trials with sheep fed ad libitum only forage or forage plus concentrate

Two in vivo digestibility trials with sheep were conducted to identify the minimum period length of feeding a new diet to obtain reproducible values of nutritional variables onward and the minimum length of collection period as to obtain maximal precision for each variable. Trial 1 was conducted with ten Polwarth male sheep (34 ± 5 kg body weight (BW)) throughout three 21‐day periods, in a completely randomized two‐way crossover design. The animals were divided into two groups (Group A and B, n = 5 per group) which were fed ad libitum with a sequence of the following diets throughout the periods: Group A: hay – hay plus concentrate – hay; Group B: hay plus concentrate – hay – hay plus concentrate. The concentrate was included in a proportion of 0.33 of the total diet. The intake, and the faecal and urinary excretion were measured daily throughout the experiment. For evaluating rumen fermentation variables, in Trial 2 four Santa Inês male sheep (65 ± 5 kg BW) fitted with ruminal cannula were used. The animals were randomly divided into two groups (n = 2 per group), and the trial was conducted through four 21 days experimental period, in a three‐way crossover design, using experimental diets and feeding management similar to Trial 1. The results indicated that, even though no clear or consistent steady‐state condition was identified for rumen fermentation or urinary excretion variables, the adaptation period for measuring OM digestibility in in vivo trials with sheep fed ad libitum where the diet shifts from one of only hay to another containing concentrate, or vice‐versa, should be at least 12 days long. Moreover, although no precision improvement was obtained by increasing the collection period above 1 day for measuring OM digestibility, the minimal length of collection period should be 4 days for measuring faecal excretion variables and 7 days for measuring urinary excretion variables.     

Effect of chelating agents on the excretion of copper,zinc and iron in the bile and urine of sheep

The effect of tetrathiomolybdate (TM), disodium calcium ethylenediamine tetraacetate (EDTA), D-penicillamine (PEN), 2-3 dimercapto-1-propanol (BAL) and dimethyl dithiocarbamate (DDC) administration on biliary and urinary excretion of copper (Cu), zinc (Zn) and iron (Fe) was investigated in sheep on a low Cu diet (Group A) and a high Cu diet (Group B). Only biliary Cu excretion increased significantly (P<0.01) with TM treatment. Urinary Cu excretion increased (P<0.01) following PEN treatment. TM, EDTA, PEN, BAL and DDC adminstration increased Cu excretion via bile and urine by 254, 11, 266, 46 and 16%, respectively in Group A sheep, and by 354, 13, 196, 20 and (-) 31% in Group B sheep. Urinary Zn excretion increased (P<0.01) following EDTA and PEN treatments. Only urinary Fe excretion increased (P<0.01) with EDTA treatment. The results show that TM and PEN are the most efficient decoppering agents, but PEN unlike TM also removes Zn. The major routes of excretion of Cu chelates by TM and PEN are different. TM increases Cu excretion significantly (P<0.05 in Group A and P<0.01 in Group B) in bile with only a slight increase in urinary Cu whereas PEN increases Cu excretion significantly (P<0.01) in urine. Therefore from a therapeutic view, a combination therapy of TM and PEN would be useful to maximize Cu removal from the body.     

Diagnosis and treatment of copper poisoning caused by accidental feeding on poultry litter in a sheep flock

We report a case of chronic copper poisoning in a flock of 182 grazing dairy sheep in Thessaly, Central Greece. Five ewes were found dead during the course of a week. The diagnosis of copper poisoning was confirmed by necropsy examination, blood test results, and abnormally high copper levels in liver and kidney samples. A field investigation revealed the source of copper as a litter heap from a broiler farm to which the sheep had accidental access during their movement between the milking parlour and the grazing area. Access to the litter was subsequently blocked and all sheep were provided with 50 g of a salt/gypsum/sodium molybdate mixture (90.0: 9.8: 0.2, w/w) mixed in 500 g of concentrate feed daily, for a period of 5 weeks. Follow-up blood samples were taken 3 and 8 wk after the initial diagnosis. A reduction in aspartate aminotransferase activity indicated the source of copper had been eliminated and the subsequent treatment was successful.     

Cryopreservation of sheep red blood cells. 1. Experiments with polyvinylpyrrolidone and other protective agents

The protection of sheep erythrocytes at freezing temperatures was investigated using glycerol, dimethylsulfoxide (DMSO), glucose and four different types of polyvinylpyrrolidone (PVP) as cryoprotective agents. Depending on type (molecular weight) and concentration good protection was obtained with PVP, whereas glycerol, DMSO and glucose were unsatisfactory. Recovery of cells after thawing was most successful when the cells had been frozen at a concentration of 1–2 × 10⁹ cells/ml. No cells tolerated freezing at −20 °G. Best results were obtained when the cells were frozen directly in liquid nitrogen (−196°G).     

Cryopreservation of sheep red blood cells. 2. Purified polyvinylpyrrolidone and hydrolyzed starch as protective agents

The protection of sheep erythrocytes against damage at low temperature (−196°C) was investigated using purified polyvinylpyrrolidone (PVP) and hydrolyzed starch as cryoprotective agents. Identical results were obtained with untreated PVP, neutralized PVP and PVP purified by chromatography. With hydrolyzed starch the cryoprotection was dependent on the type and concentration of the starch used and on the extent of hydrolysis of the starch prior to use. Cell recovery with some starch types was the same (80–85 %) as that obtained with PVP.     

Urinary excretion of purine derivatives and plasma allantoin level in sheep and goats during fasting

The relationship between blood plasma level and urinary excretion of allantoin (AN) was examined in sheep and goats during fasting to investigate the possible use of purine derivatives (PD) in urine and/or plasma for estimating the microbial protein production in the rumen, and the further digestion in the lower guts of ruminants. Urinary AN excretion decreased markedly during fasting (0.13 mmol/kgW^0.75 per day), although urinary levels of other PD, hypoxanthine + xanthine and uric acid did not differ irrespective of the feeding condition, that is, feeding, fasting and refeeding in both species. The AN concentration in blood plasma also decreased drastically in the starvation period, and was suddenly increased on refeeding in sheep and goats, and these phenomena were very similar to those of urinary AN excretion. Therefore, there was a high positive correlation between plasma AN level and urinary AN excretion, and the coefficient of correlation was statistically significant (P < 0.01). These results clearly indicate that changes in urinary AN reflect change in plasma AN, which is induced by the catabolism of purine base in the body.     

巴什拜羊、盘羊杂交羊重组SP-A蛋白对体外培养MO增殖的影响

为研究巴什拜羊和盘羊杂交羊的重组肺表面活性物质相关蛋白A(rSP-A)对体外培养的绵羊肺炎支原体(MO)增殖的影响,本研究利用不同浓度(10μg/mL、20μg/mL和40μg/mL)巴什拜羊和盘羊杂交羊的rSP-A添加于MO培养液中进行体外培养,采用平板菌落计数和荧光定量PCR方法检测其对MO增殖的影响。平板菌落计数结果显示,巴什拜羊的3个rSP-A浓度组菌落数分别比对照组减少了8.35%(p>0.05)、23.04%(p<0.05)和40.03%(p<0.01);盘羊杂交羊的3个rSP-A浓度组菌落数分别比对照组减少了6.73%(p>0.05)、21.74%(p<0.05)和37.11%(p<0.01)。荧光定量PCR检测结果显示,添加rSP-A培养4h后MO16SrRNA基因拷贝数降至最低,巴什拜羊3个rSP-A浓度组16SrRNA基因拷贝数比对照组下降了72.15%(p<0.05)、78.81%(p<0.01)、81.48%(p<0.01);盘羊杂交羊的3个rSP-A浓度组的MO16SrRNA基因拷贝数比对照组下降了26.26%(p>0.05)、76.62%(p<0.01)、80.83%(p<0.01)。研究表明,巴什拜羊和盘羊杂交羊的rSP-A对体外培养的MO具有明显的抑制作用。本研究比较了不同品种羊SP-A蛋白在抗MO感染中的作用,为进一步研究盘羊杂交羊易感MO的分子作用机制奠定基础。     

The toxic effects of dimethylnitrosamine in sheep

Experimental feeding, dealing with long term ingestion of small daily doses of DMNA has clearly demonstrated the cumulative toxic effect of this compound in sheep. A threshold level, somewhere between 0.10 mg and 0.15 mg DMNA/kg body weight per day, can be defined below which no toxicity even in quite long-lasting feeding can be demonstrated. Above this level toxicity changes will develop, clinically in most cases, anatomically in all, if the exposure time is long enough. If the daily intake of DMNA is over this threshold level, 21–40 mg DMNA/kg body weight, it usually causes liver disease and death in sheep. Neoplastic lesions were not produced, the experimental period, however, was below the latency period for carcinogenesis.     

湖羊杂交组合筛选试验研究

将陶赛特、萨福克、杜泊、澳洲白羊作父本与湖羊母羊开展杂交试验,杂交一代分别与纯繁湖羊(湖×湖)进行生产性能及肉品质比较,以期筛选出适宜推广应用的杂交模式。结果:杂交一代的父本特征和杂种优势明显,3、6和10月龄体重显著高于湖×湖组(P<0.05),且以陶×湖组最高;10月龄屠宰,杂交一代组胴体重比湖×湖组平均高3.24 kg,其中陶×湖、杜×湖杂一代显著高于湖×湖组(P<0.05),以陶×湖杂一代最高;各组肉中氨基酸总量、必需氨基酸含量/氨基酸总量和必需氨基酸含量/非必需氨基酸含量均显著高于联合国粮农组织推荐的优质蛋白质组成中氨基酸水平;总多不饱和脂肪酸酸含量/总饱和脂肪酸含量以萨×湖组最高、湖×湖组最低。综合分析各项指标,以陶×湖杂交组合效果最优。     

Listeriosis in sheep. Listeria monocytogenes excretion and immunological state in healthy sheep.

Listeriosis in sheep. Listeria monocytogenes excretion and immunological state in healthy sheep. Acta vet. scand. 1979, 20, 168–179. — The excretion of Listeria monocytogenes (Lm) in the faeces and milk, and humoral and cell mediated immunity against Lm, were examined in a sheep flock where no cases of listeriosis had occurred during the last 3 years. The investigation was carried out during the indoor season. During the first part of the season 2 of the 10 pregnant, 8 months old lambs excreted Lm in the faeces, but none of the 106 ewes, 2–10 years old. At lambing the organism was isolated from the faeces of 6 of the 10 1 year old lambs and from 64% of the ewes, and from the milk of 1 of the lambs and 41% of the ewes. Nearly all the isolates (98.5%) belonged to serotype 1.Antibody titres against Lm were found in sera and whey by an indirect haemagglutination method. The titres were higher for the ewes than for the hoggs and seemed to be influenced by the number of foetuses the animals carried.Cell mediated immunity was determined by a skin test where delayed hypersensitivity against an antigen prepared from Lm, was measured. Animals fed grass silage had a stronger reaction than animals fed hay, and a stronger reaction was found in animals with ≥ 3 foetuses than in the remainder.The investigation indicates that even in a healthy sheep flock all the animals may be exposed to Lm, and the majority may be latent carriers and excrete this organism in the faeces and milk during periods of stress.     

Copper deficiency in sheep: An assessment of the relationship between concentrations of copper in serum and plasma

AIM: To assess the relationship between concentrations of copper in serum and plasma in sheep.

METHODS: Concentrations of Cu were measured in paired serum and heparinised plasma samples collected from 110 sheep in nine flocks. Linear regression was used to evaluate whether flock or gender had a significant effect on the association between concentrations of Cu in serum and plasma. The individual results for concentrations of Cu in serum were then compared with those from plasma, using correlation and limits of agreement plotting.

RESULTS: Concentrations of Cu in serum ranged from 7.3 to 22 (mean 14.0) µmol/L, while concentrations in plasma ranged from 9 to 27 (mean 16.3) µmol/L. On average, concentrations of Cu in serum were 2.3 µmol/L lower than in plasma. Over the range of values seen in this study, concentrations of Cu in plasma and serum were significantly correlated (r=0.89), and mean concentrations in serum were 87% of those in plasma. There was no effect of flock or gender on the relationship between concentrations of Cu in serum and plasma. Despite the significant correlation, there was marked variability between individual samples in the proportion of Cu that was lost during clotting, with the 95% limits of agreement for serum Cu ranging from 70 to 104% of the plasma concentration.

CONCLUSIONS: As in cattle, the individual variability in the loss of Cu during clotting in sheep is too great for concentration of Cu in serum to be used as a substitute for that in plasma.

CLINICAL RELEVANCE: When assessing the blood Cu pool as part of the diagnosis of Cu-responsive disease in sheep, the concentration of Cu in plasma should be measured in preference to that of serum. We suggest that a range of 4.5 to 9 µmol/L in plasma be used to define marginal Cu status in sheep.     

绵羊基因组中内源性绵羊肺腺瘤病毒相关序列的确定

绵羊都含有与绵羊肺腺瘤病毒(Jaagsiekte sheep retrovirus,JSRV)密切相关的15~20拷贝内源性绵羊肺腺瘤病毒(enJSRV)相关序列。宿主可利用内源性病毒来预防致病性反转录病毒的感染,一些内源性病毒可以有效地干扰相关外源性病毒的复制。本试验通过分子生物学手段确定了蒙古绵羊基因组中含有enJSRV6和enJSRV10两个内源性病毒基因而内蒙古白绒山羊中未发现。通过比较内、外源病毒LTR序列的酶切图谱,获得专一作用外源性病毒的核酸内切酶M spⅠ、TfiⅠ、BsaWⅠ,如果将酶切与聚合酶链式反应(PCR)相结合,不需要经过测序就可分辨enJS-RV和外源性绵羊肺腺瘤病毒(exJSRV),形成"酶切-PCR"检测技术,将为绵羊肺腺瘤病的快速诊断提供了新的手段。