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1.
Orf, a viral disease which causes proliferative skin lesions around the mouths of lambs and on the teats of ewes, has long been assumed to have production-limiting consequences. This case-control study involved the collection of data from naturally occurring outbreaks of orf in young lambs on eight commercial farms in north-east England. Measurements of weight were taken and orf lesions were scored on a numerical scale for 44 orf-affected lambs, matched to unaffected controls within the same group. Data from corresponding ewes were available from five farms. Paired t tests showed that affected lambs weighed approximately 10 per cent less than their unaffected controls for a period of at least five weeks following the start of the outbreak. The effects were highly significant whether the orf lesions affected the mouth or were found elsewhere on the body. If a lamb had orf, then there was a 82 per cent chance that its mother also had orf on its udder or teats. The financial consequences of orf in young lambs were estimated using average UK figures and conservative assumptions based on the results of this study.  相似文献   

2.
The toxicity of serpentine phosphate and superphosphate for non-pregnant dry ewes, pregnant ewes and lactating ewes was investigated by oral dosing. An attempt was made to reproduce a natural episode of poisoning by exposing pregnant and lactating ewes to topdressed pasture. A total dose in the range of 1200 to 1800 g of serpentine phosphate was required to kill two ewes and it was concluded that natural episodes of poisoning with this material are unlikely. The toxic process was similar to that caused by superphosphate. The LD50 of superphosphate was estimated to be in the range of 5 to 6 g/kg and a dose in the range of 200 to 300 g was sufficient to kill most sheep. The apparently greater susceptibility of pregnant and lactating sheep to poisoning suggested by the study of natural outbreaks was not demonstrated in these experiments, but the numbers of experimental animals may have been too small to detect differing susceptibility. The clinical disease resembled that seen in natural episodes; anorexia, diarrhoea, progressive depression and death in a period of 5 to 8 days after the start of dosing. Sublethal doses produced a transient diarrhoea and, in two sheep, a severe wool-break. The principal biochemical changes were hyperphosphataemia and evidence of renal failure (oliguria, uraemia, azotaemia). Gross lesions were not consistently present but included abomasal ulceration and renal cortical swelling and pallor. The histopathological evidence of renal tubular obstruction by flocculant eosinophilic casts was characteristic.  相似文献   

3.
The toxicity of serpentine phosphate and superphosphate for non-pregnant dry ewes, pregnant ewes and lactating ewes was investigated by oral dosing. An attempt was made to reproduce a natural episode of poisoning by exposing pregnant and lactating ewes to topdressed pasture.

A total dose in the range of 1200 to 1800 g of serpentine phosphate was required to kill two ewes and it was concluded that natural episodes of poisoning with this material are unlikely. The toxic process was similar to that caused by superphosphate.

The LD50 of superphosphate was estimated to be in the range of 5 to 6 g/kg and a dose in the range of 200 to 300 g was sufficient to kill most sheep. The apparently greater susceptibility of pregnant and lactating sheep to poisoning suggested by the study of natural outbreaks was not demonstrated in these experiments, but the numbers of experimental animals may have been too small to detect diiering susceptibility.

The clinical disease resembled that seen in natural episodes; anorexia, diarrhoea, progressive depression and death in a period of 5 to 8 days after the start of dosing. Sublethal doses produced a transient diarrhoea and, in two sheep, a severe wool-break.

The principal biochemical changes were hyperphosphataemia and evidence of renal failure (oliguria, uraemia, azotaemia). Gross lesions were not consistently present but included abomasal ulceration and renal cortical swelling and pallor. The histopathological evidence of renal tubular obstruction by flocculant eosinophilic casts was characteristic.  相似文献   

4.
The uterine tubes from 405 ewes, collected at an abattoir, were assessed grossly and microscopically for abnormalities that correlated with serological evidence of exposure to Chlamydophila abortus. Gross lesions were found in 41 ewes and 86 had microscopic lesions. Enzyme immunoassay (EIA) of serum was used as an indication of exposure of individual ewes to C. abortus; 52 were found to be positive. Chi-squared analysis indicated no association between EIA-positive animals and lesions of the uterine tube.  相似文献   

5.
Eleven maiden Merino ewes, free of antibody to bluetongue virus serotype 20 (BTV-20) in agar gel immunodiffusion and serum neutralisation tests, were mated once with a ram. Ten ewes were inoculated with BTV-20 35 to 42 days after service, and one ewe was left as an uninoculated control. One of the inoculated ewes and the control ewe remained uninfected throughout the experiment. Eight of the remaining 9 ewes showed clinical signs ranging from mild to moderate, and the other showed no clinical signs of infection. BTV-20 viraemia was detected in ewes between days 3 and 11 post inoculation, and the serum antibody response was followed. The control ewe and 5 of the 9 infected ewes were pregnant when examined 90 to 97 days after service. Each of these animals produced a normal lamb. There was no evidence of abortion in the remaining 5 ewes, and no transplacental transfer of virus was detected in the lambs of the 5 infected ewes. At necropsy, 46 days after the birth of the last lamb, no gross or microscopic lesions were observed in either the ewes or lambs.  相似文献   

6.
Two groups of pregnant ewes were experimentally infected oronasally in midpregnancy. A faecal and an abortion-source isolate of Chlamydophila abortus were used. They were derived from a healthy ewe from a flock with no history of abortion, and from an aborted foetus in a farm with enzootic abortion. As assessed by modified Ziehl-Neelsen (MZN) staining, egg culture, antigen ELISA, the Clearview test and immunohistochemistry, inoculation resulted in placental and/or foetal infection in all ewes. Histopathology revealed placentitis in two and four ewes inoculated with the enteric or abortion-source isolate, respectively, in addition, these samples were immunohistochemically positive for chlamydial antigen. All six ewes infected with the enteric isolate and five of seven ewes infected with the abortion-source isolate showed evidence for a serological response by an indirect ELISA or CFT. Neither chlamydiae nor lesions were detected in the placentae and lambs of the uninfected control ewes, which remained seronegative. Our results suggest that enteric C. abortus can be associated with placental and foetal lesions in sheep.  相似文献   

7.
Objective of the work was to study whether Mannheimia haemolytica may be transmitted from the mouth of the lambs into the teat of the dam during sucking. We compared bacterial populations within the teat duct and milk of ewes immediately before and immediately after sucking by the lambs. Tonsils of lambs of the ewes were swabbed. M. haemolytica strain DAG21T recovered from a teat duct of a ewe was compared to strain DAG21R recovered from the tonsils of her lamb by using 16s rRNA sequencing. We used those two isolates and another one of known pathogenicity, for challenging ewes: (i) 2-mm deep into healthy teats, (ii) 2-mm deep into teats with chapping lesions or (iii) into the cistern of healthy mammary glands. Of samples collected before suckling, 20/792 were bacteriologically positive, and of those after, 50/792 were bacteriologically positive (P < 0.001); in 37 cases, a negative sample became positive. One M. haemolytica (DAG21T) was recovered after suckling from a teat duct of a ewe. The organism was isolated from 57/90 tonsillar swabs from lambs. Risk of infection of ewe’ teats was 0.004 throughout lactation, being greatest (0.021) during the 3rd week of lactation. The 16s rRNA sequences of strains DAG21T and DAG21R were identical over 1450 nucleotides. Phylogenetic analysis showed that the two isolates clustered together with isolates of M. haemolytica. Organism deposition into healthy teats caused subclinical mastitis; deposition into teats with lesions or directly into mammary gland caused clinical mastitis. When results of inoculation of the three strains were compared between them, statistical significance was always P > 0.9. Results provide clear evidence that suckling by lambs can lead to transmission of M. haemolytica into the teats of the ewes; the bacteria have the potential to cause mastitis if circumstances are favourable.  相似文献   

8.
Three crossbred lowland ewes developed a severe purulent rhinitis and another three ewes developed a severe purulent otitis externa/media after being showered with a wash that had been used 24 to 48 hours before on a separate group of Cheviot ewes with lesions of dermatitis. Pseudomonas aeruginosa was isolated in pure growth from the aural and nasal abscesses and also from the dermatitis lesions. Extended antibiotic susceptibility testing and the random amplification of polymorphic DNA indicated that a single clonal type was associated with the rhinitis and otitis and with the dermatitis, providing strong evidence of an epidemiological link between the lesions of dermatitis and the aural and nasal abscesses through the use of the contaminated 'shower wash'.  相似文献   

9.
In order to provide further evidence for the association of an indurative lymphocytic mastitis in sheep with MVV (maedi-visna virus) infection, an experimental study was performed. Fourteen MVV-free pregnant ewes, 2 years of age, were divided into two groups. Eight were intravenously inoculated with MVV (strain ZZV-1050); six ewes served as sham-inoculated controls. Post-mortem examinations were carried out at 8, 16 and 28 months. After 8 months, the 3 infected ewes had indurated udders with extensive lymphoid proliferation around lactiferous ducts and in the acinar tissue. The ducts were often partially obliterated. After 16 months, one of the two infected ewes suffered from indurative lymphocytic mastitis. The other was free of specific udder lesions. After 28 months only one of three infected ewes had mild lymphocytic infiltration in the udder. None of the controls, two in each post-mortem session, had lesions typical of this form of mastitis. The lesions were most severe 8 months after infection. At 16 and 28 months lesions were of a lesser degree or were absent. The lung lesions in the infected ewes 8 months after inoculation were similar to the changes in the udder regarding the lymphoid accumulation, although the proliferation around bronchial tree and blood vessels was less pronounced. After 16 and 28 months all infected ewes had peribronchial and perivascular lymphocytic infiltration though of a lesser degree than after 8 months. From these results it is concluded that in addition to the lung and brain lesions MVV infections may cause a specific indurative lymphocytic mastitis.  相似文献   

10.
The roles of age, tail length and the Mules operation in the epidemiology of squamous cell carcinoma in ewes were studied. The prevalence of the disease in adult sheep slaughtered at 2 abattoirs was 0.08%. No cases occurred in lambs. Of all adult sheep condemnations before slaughter, 38.5% were due to squamous cell carcinoma. Of these sheep, 73.3% had a single lesion of the vulva (62.9%), tail (6.6%), or anus (3.8%), while 26.7% had lesions at more than one site. The number of lesions was significantly greater (p < 0.01) in sheep with a radical Mules operation than in those with a modified Mules operation or not mulesed. Tails were significantly shorter (p < 0.01) in affected than unaffected sheep. Small keratinised outgrowths on the skin of the tail and perineum were considered on histological grounds to be precursors of squamous cell carcinomas. On one affected farm 4% of ewes were culled in one year for gross lesions of squamous cell carcinomas. A further 3.5% of sheep with gross lesions and 25.3% with precursor lesions remained in the flock, undetected by the farmer. Gross lesions were not observed in ewes under 3 years of age, whereas precursors occurred in all age groups, including one-year-old ewes. The prevalence of lesions increased with age, from 0.43% in 5-year-old ewes to 5.14% in 6-year-old and 41% in 7-year-old ewes. Discriminant analysis indicated that age of ewe, tail length and the width of the healed Mules operation were important determinants of squamous cell carcinoma. In all the sheep studied the style of mulesing was consistently radical, with a mean healed width of 12.3 ± 2.6 cm. Tails were amputated much shorter than the traditionally recommended length of level with the tip of the vulva. The presence of gross and precursor lesions was associated with shorter tails and a radical Mules operation. It is suggested that the prevalence of the disease may be reduced by the adoption of a less severe mulesing technique and leaving tails longer.  相似文献   

11.
Abnormalities of the reproductive tract of female sheep were studied by examining 9970 reproductive tracts from cull ewes and 23,536 tracts from nulliparous sheep (prime lambs) over a period of 12 months in abattoirs in south-west England. Overall, 3.37 per cent of the tracts were pregnant (8.11 per cent of cull ewes, and 1.36 per cent of nulliparous sheep), with a peak incidence between September and December. A total of 655 ewes (6.57 per cent) and 459 nulliparous sheep (1.95 per cent) had acquired abnormalities of the reproductive tract. Within these totals, abnormalities of the ovaries accounted for 3.51 per cent (for the ewes) and 10.68 per cent (for the nulliparous sheep) of all the abnormalities, and abnormalities of the ovarian bursa and uterine tube accounted for 42.1 per cent (for the ewes) and 5.23 per cent (for the nulliparous sheep). In addition, uterine lesions (hydrometra and metritis) accounted for 9.92 per cent (for the ewes) and 13.51 per cent (for the nulliparous sheep); lesions of the cervix and vagina (total of 1.44 per cent) and Cysticercus tenuicollis cysts associated with the reproductive tract (total of 3.05 per cent) were less common. Among the ewes the most common ovarian lesions were ovulation tags, and follicular cysts were the most common in nulliparous animals. Lesions such as bursitis, parametritis and abscesses of the reproductive tract were much more common in cull ewes than in nulliparous sheep, probably having arisen from peripartum infections. Hydrosalpinx and hydrometra, in which the intraluminal fluid was clear, were present at relatively high incidence in nulliparous animals, but not in cull ewes. The proportion of tracts containing macerated fetal remnants (2.14 per cent of all abnormalities in cull ewes) was lower than expected. It was considered that the functional significance of many of the lesions, such as ovulation tags and C tenuicollis cysts, was likely to be low, although in some cases of the latter calcification of the cyst had occluded the uterine tubes. Other lesions, notably hydrosalpinx, bursitis and metritis were likely to have made the affected animals sterile. The acquired abnormalities were therefore more significant in terms of individual animal infertility than as a major cause of infertility in flocks.  相似文献   

12.
An accidental infection from a vaccine was suggested as the explanation for the sudden increase in outbreaks of scrapie in Italy in 1997 and 1998. This paper describes a recent outbreak of scrapie in sheep and goats which were exposed to the same vaccine. No ewes or goats had been imported into the herd since 1992, but a vaccine against Mycoplasma agalactiae had been administered twice, in 1995 and 1997. High rates of crude mortality and scrapie incidence were experienced by both species, all birth cohorts were involved and a large proportion of aged animals was affected. A pattern of brain lesions was observed, with slight differences between the sheep and goats, which was very similar to the pattern observed in animals previously exposed to the same vaccine but clearly different from that observed in the brains of sheep with scrapie in a flock not exposed to the vaccine. Regardless of their exposure status, genotype analysis of the sheep showed the presence of polymorphism only at codon 171. The patterns of both incidence and brain lesions provide evidence that the epidemic of scrapie was due to the use of the vaccine.  相似文献   

13.
Summary

In order to provide further evidence for the association of an indurative lymphocytic mastitis in sheep with MVV (maedi‐visna virus) infection, an experimental study was performed. Fourteen MVV‐free pregnant ewes, 2 years of age, were divided into two groups. Eight were intravenously inoculated with MVV (strain ZZV‐1050); six ewes served as sham‐inoculated controls. Post‐mortem exat. inations were carried out at 8, 16 and 28 months.

After 8 months, the 3 infected ewes had indurated udders with extensive lymphoid proliferation around lactiferous ducts and in the acinar tissue. The ducts were often partially obliterated. After 16 months, one of the two infected ewes suffered from indurative lymphocytic mastitis. The other was free of specific udder lesions. After 28 months only one of three infected ewes had mild lymphocytic infiltration in the udder. None of the controls, two in each post‐mortem session, had lesions typical of this form of mastitis. The lesions were most severe 8 months after infection. At 16 and 28 months lesions were of a lesser degree or were absent.

The lung lesions in the infected ewes 8 months after inoculation were similar to the changes in the udder regarding the lymphoid accumulation, although the proliferation around bronchial tree and blood vessels was less pronounced. After 16 and 28 months all infected ewes had peribronchial and perivascular lymphocytic infiltration though of a lesser degree than after 8 months.

From these resutls it is concluded that in addition to the lung and brain lesions MVV infections may cause a specific indurative lymphocytic mastitis.  相似文献   

14.
Attempted venereal transmission of Chlamydia psittaci in sheep   总被引：2，自引：0，他引：2  
Attempts were made to transmit Chlamydia psittaci, the causal agent of enzootic abortion of ewes, in three different ways. Ten ewes were inseminated artificially with freshly collected semen containing 10(5) CELD50 chlamydia. Serological evidence of infection was found two weeks before parturition in nine ewes and the organism was recovered from three of them. By six weeks post partum antibody titres had fallen and were negative in six ewes. Twenty-four hours after service two groups of 10 ewes were infected intravaginally with 10(8) CELD50 and 10(3) CELD50 chlamydia respectively. Positive complement fixation titres were present in the first half of pregnancy in all the ewes in the high dose group but not the low dose group. None of the ewes showed evidence of infection at parturition. Fourteen ewes were served by four rams which had been intravenously infected with 10(8) CELD50 chlamydia four to six days earlier. Following service seroconversion occurred but titres became negative again by late pregnancy. No microbiological evidence of infection was detected in any of the ewes at parturition but complement fixation titres were positive in 12 of 14 ewes sampled six weeks post partum. The 14 ewes were sampled during their pregnancies the next year and none showed any evidence of chlamydial infection. It is concluded that venereal transmission of C psittaci is biologically feasible in sheep, but that under normal systems of flock management in Britain it is unlikely to contribute greatly to the epidemiology of enzootic abortion of ewes.  相似文献   

15.
A field trial was set up to determine the effects of mechanical shortening of long incisors (bite correction) of ewes with early periodontal disease on the progress of the disease and on their body weights. On a farm near Te Anau with a high prevalence of periodontal disease in sheep, the body weights of 75 sound mouth ewes and two groups each of 75 ewes with periodontal disease were recorded. At the start of the trial, the incisors of the ewes in one of the groups with periodontal disease were shortened using a grinder. The trial ran for 2 years. The mouths of almost all the sheep which had sound mouths at the start of the trial remained sound throughout. This suggests that on periodontal disease-prone farms it may be possible to select ewes at 3 or 4 years of age which will retain sound mouths throughout much of thei-r productive lives. Throughout the trial, sheep with advanced periodontal disease tended to be lighter than sheep with mild periodontal disease and those in turn tended to be lighter than sheep with sound mouths. Mechanical shortening of the incisors did not alter the proportion which subsequently developed advanced periodontal disease. Seventeen to eighteen percent of ewes in both periodontal disease groups had developed advanced periodontal disease by the end of the trial. There was no significant difference in body weight between the group with shortened incisors and the group with untreated periodontal disease. Consequently, the trial provides no evidence that the mechanical shortening of the incisors of ewes will improve their productivity.  相似文献   

16.
It was the objective of this study to quantify heat production across ages of Rambouillet and Finnsheep ewes and to evaluate the previous hypothesis that breed differences can be accounted for by scaling for proportion of mature body weight. Seventy-two Finnsheep and 55 Rambouillet ewes were sampled. Heat production was estimated based on individual animal gaseous exchange, which was determined from 55 through 71 h of the feed restriction. Heat production per unit BW decreased as sheep aged, and the breed-specific functions fit the data better than the pooled functions. The rate of decrease in heat production was greater in Finnsheep ewes until 37 wk of age. The rate of growth of Rambouillet ewes was greater than that of Finnsheep ewes over the first 52 wk of age, and Rambouillet ewes reached 95% of their mature BW at an earlier age (71 wk) than did Finnsheep ewes (113 wk). At any given age, Rambouillet ewes had achieved a greater proportion of their mature BW and had a lower heat production per unit BW than Finnsheep ewes. This study demonstrated the necessity of accounting for both age and breed when estimating metabolic rate in sheep. Furthermore, this study suggested that breed and age differences in metabolic rate could be accounted for by scaling for proportion of mature BW and that daily heat production per unit BW (kcal/kg) of Finnsheep, Rambouillet, Suffolk, and Texel ewes can be described by the function /(BW, matBW) = 59.5e(-0.797(Bw/matBw)), where BW = body weight and matBW = mature body weight.  相似文献   

17.
Maedi-visna (MV) is a relatively common chronic infection of sheep in North America resulting in economic loss to the sheep industry. The objectives of this study were to: 1) measure the prevalence of MV infection in culled ewes in Alberta, by histologic examination (lungs and udder) and serologic testing using an agar gel immunodiffusion (AGID) test, 2) examine any geographic differences in its prevalence in the province, 3) evaluate the level of agreement between histopathologic examination and serologic testing, 4) grade the lesions and correlate the serologic results with the presence of severe histological lesions, and 5) correlate the presence of histological lesions in the lungs and udder in the same animal. Based on histologic findings, the prevalence of MV was 26.8%, compared with 13.0% using serologic testing. There were no significant geographical differences in prevalence, fair agreement (kappa = 42.0%) between histopathologic and serologic results, and poor agreement (kappa = 11.5%) between the presence of lung and udder histological lesions within the same animal. This study indicates that MV is relatively common in culled ewes in Alberta, with no significant geographic variation. The poor sensitivity of the AGID test, compared with histologic examination, should be taken into consideration when interpreting serologic results.  相似文献   

18.
In this study we evaluated maternofetal transmission of immunoglobulins in ewes under conditions of altered placental morphology. Intravenous injection of human red blood cells was used to induce immunoglobulins in pregnant ewes. The hemagglutination test was used to detect antibody in maternal serum, fetal and placental fluids. Placental injury was induced by intravenous inoculation of Escherichia coli endotoxin or spores of Aspergillus fumigatus into pregnant ewes at days 99 or 100 of gestation respectively. Placental infarction, thrombosis of maternal placental vessels and variable neutrophil infiltrate characterized lesions produced by A. fumigatus. Endotoxin treated ewes developed marked placental edema, congestion, hemorrhage and focal loss of uterine epithelium. Human red blood cell agglutinating antibody was not detected in placental or fetal fluids obtained from ewes with either of the above placental lesions. Placentitis of undetermined etiology was observed in seven ewes. Two ewes had received A. fumigatus, two had received endotoxin and three were untreated ewes. Histological examination of their placentas revealed trophoblastic and endometrial epithelial necrosis and necrotizing vasculitis of the chorioallantois. Human red blood cell agglutinating antibody was detected only in the fetal and placental fluids of the seven ewes with these placental lesions. The nature of these lesions would have produced a functional confluence of the maternal and fetal circulations. Antibody transfer from dam to fetus was observed only in association with placental lesions which produced this confluence of circulations. The character of the placental lesions, rather than the mere presence of placental lesions apparently determined the transfer of immunoglobulins.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

19.
本试验旨在通过构建模型,利用计算机技术识别母羊发情的叫声。对40只崂山奶山羊发情、羔羊寻母、母羊饥饿和饲料刺激4种类型声音进行录制,通过搭建程序对原始声音进行声音信号分析,然后将声音进行预处理并进行特征参数提取,发现母羊发情、饥饿、羔羊寻母状态下羊的声音强度和频率有显著差异。利用隐马尔可夫模型(HMM)、支持向量机(SVM)和迭代算法(Adaboost)3种声音模型对羊声音进行识别准确率验证,结果显示3种声音模型识别羊的发情状态与试情结果吻合率为96.67%、84.17%和87.92%。从动物行为学的角度分析,可以利用计算机处理羊的声音识别出母羊发情等状态。  相似文献   

20.
Campylobacter jejuni was inoculated intravenously into pregnant ewes on gestation days 114 and 123 to reproduce ovine abortion. All ewes aborted 7-12 days post-inoculation. High numbers of C. jejuni were isolated from ewe tissues (caruncle, bile, cecal feces), fetal tissues, and placenta. C. jejuni colonies were identified in caruncles and placenta by light microscopy and immunoperoxidase techniques. Histologically, inoculated ewes had a severe purulent endometritis with vasculitis. Placentas from inoculated ewes and field cases showed necrosis and purulent inflammation; however, placentas from inoculated ewes had large numbers of bacterial colonies compared to few bacteria found in field cases. Histologically, only one fetus from the inoculated ewes showed lesions (purulent bronchopneumonia), whereas all fetuses from field cases had a distinct bronchopneumonia, and one fetus showed multifocal hepatic necrosis. These results suggest that C. jejuni (serotypes Penner 1 and Lior 2) is an important abortifacient organism for sheep.  相似文献   

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