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1.
The prevalence, incidence and clinical signs of listeriosis in dairy cattle in England were investigated by means of a postal questionnaire survey of 1500 dairy farmers. The response rate was 64.1 per cent. Overall the farm prevalence of listeriosis was 11.7 per cent, 9.3 per cent for milking cows, 5.0 per cent for replacement heifers and 1.4 per cent for dairy calves. The within-herd incidence rate per thousand animal-years was 51.4 for all cases, 39.7 for milking cows, 86.6 for replacement heifers and 73.7 for dairy calves. Most cases of clinical listeriosis were reported between December and May, and the most common signs were silage eye, followed by nervous signs. The results of the questionnaire were validated internally by re-estimating the farm prevalence by including only those cases diagnosed by a veterinarian or veterinary investigation centre; the prevalence did not change significantly. The proportion of cases which were culled or died of encephalitic listeriosis was compared with the proportion diagnosed during statutory BSE reporting. The fact that the two proportions were similar provided external validation for the results of the questionnaire.  相似文献   

2.
The prevalence of urinary tract infections in calves aged seven days to three months in three dairy cattle herds ranged from 0.5 to 1.6 per cent, with an average of 1.1 per cent. The mortality rate reached 16.1 per cent. The morbidity rate of the female calves was 1.4 per cent and that of the male calves 0.8 per cent. The bacteria isolated from urine, and from vaginal and preputial swabs were Escherichia coli (35 per cent), Corynebacterium renale (14 per cent), plasma coagulase-negative Staphylococcus species (12 per cent), Pseudomonas aeruginosa (12 per cent), Proteus species (12 per cent) and Arcanobacterium pyogenes (5 per cent). The affected calves had a significantly lower serum concentration of inorganic phosphorus (P < 0.01).  相似文献   

3.
Faecal samples from 434 calves under 1 year of age (307 diarrhoeal and 127 normal) were collected from three dairy farms and one village in selected areas of Bangladesh. The samples were tested by an enzyme-linked immunosorbent assay (ELISA) to detect the presence of rotavirus antigen. Of 402 dairy calves tested, 28 (7.0%) were positive, of which 21 (7.2%) were from diarrhoeic calves and 7 (6.3%) from non-diarrhoeic calves. Rotavirus infection varied from farm to farm (2.7–9.2%) and there was no positive response from any of the 32 village calves. Rotavirus was most commonly found in calves of 1 week of age or less (up to 22.2% in one group) but was not found in any calves later than 6 months of age. More than 80% of rotavirus-positive samples from diarrhoeic calves exhibited a titre of 128 or more (geometric mean 345±4.5), whereas non-diarrhoeal calves had titres less than or equal to 128 (geometric mean=29±1.9), suggesting that rotavirus infection in calves in Bangladesh was mostly associated with diarrhoea.  相似文献   

4.
Microbiology of calf diarrhoea in southern Britain   总被引:9,自引:0,他引:9  
Faeces samples from calves with diarrhoea in 45 outbreaks were examined for six enteropathogens. Rotavirus and coronavirus were detected by ELISA in 208 (42 per cent) and 69 (14 per cent) of 490 calves respectively; calici-like viruses were detected by electron microscopy in 14 of 132 calves (11 per cent). Cryptosporidium were detected in 106 of 465 (23 per cent), Salmonella species in 58 of 490 (12 per cent) and enterotoxigenic Escherichia coli bearing the K99 adhesin (K99+ E coli) in nine of 310 calves (3 per cent). In the faeces of 20 per cent of calves with diarrhoea more than one enteropathogen was detected; in 31 per cent no enteropathogen was found. Faces samples from 385 healthy calves in the same outbreaks were also examined. There was a significant statistical association of disease with the presence of rotavirus, coronavirus, Cryptosporidium and Salmonella species (P less than 0.001). Healthy calves were not examined for calici-like viruses and the association of K99+ E coli with disease was not analysed because there were too few positive samples. Rotavirus infections were more common in dairy herds and single suckler beef herds whereas Salmonella infections were more often found in calf rearing units. Cryptosporidium were more common in single and multiple suckler beef herds. K99+ E coli were found in one dairy herd and one multiple suckler beef herd both with unhygienic calving accommodation. Variations in coronavirus detection among different farm types were not statistically significant. In this survey rotavirus was the most commonly detected agent in calf diarrhoea and Cryptosporidium were found in approximately one quarter of affected calves. Infection with Salmonella species was widespread, but K99+ E coli infections were less common in the United Kingdom than in other countries.  相似文献   

5.
The prevalences of Cryptosporidium parvum, rotavirus, bovine coronavirus (bcv), and enterotoxigenic Escherichia coli (E coli k99) were determined in diarrhoeic dairy calves aged one to 21 days on 71 dairy farms in western Switzerland during the winter of 2005 to 2006. Faecal samples from 147 untreated calves suffering from acute diarrhoea were analysed by standardised diagnostic methods, and the immunoglobulin status of each calf was evaluated. The prevalences of C parvum, rotavirus, bcv and E coli k99 were 55.0 per cent, 58.7 per cent, 7.8 per cent and 5.5 per cent, respectively. The proportions of herds positive for the respective pathogens among the herds with diarrhoeic calves were 41.7 per cent, 52.1 per cent, 2.1 per cent and 2.1 per cent. The immunoglobulin concentration in the serum of 90.5 per cent of the diarrhoeic calves was below 8 g/l.  相似文献   

6.
Aetiology of diarrhoea in young calves   总被引:9,自引:0,他引:9  
Faeces samples were collected from 302 untreated calves on the day of onset of diarrhoea and from 49 healthy calves at 32 farms experiencing outbreaks of diarrhoea. At least four diarrhoeic calves were sampled on each farm, and samples were examined for rotavirus, coronavirus, cryptosporidium, enterotoxigenic Escherichia coli and Salmonella species. Although all these enteropathogens were excreted more frequently by the diarrhoeic than by the healthy calves, the difference was significant overall only for rotavirus. Rotavirus was excreted by 18 per cent of healthy calves, coronavirus by 4 per cent, cryptosporidium by 14 per cent, and no enterotoxigenic E coli or Salmonella species were detected. The most common enteropathogen in diarrhoeic calves was rotavirus, which was excreted by more than half the diarrhoeic calves on 18 farms. Coronavirus was excreted at a similar high prevalence on one farm, cryptosporidium on five farms and enterotoxigenic E coli on three farms. Concurrent infection with two or more microorganisms occurred in 15 per cent of diarrhoeic calves. There was no difference in the isolation rate of campylobacters between diarrhoeic and healthy calves.  相似文献   

7.
The period between birth and first suckling was recorded for 82 dairy calves. 11 per cent of heifers' calves and 46 per cent of cows' calves had not suckled by 6 h after birth. All calves, whether suckling spontaneously or put to the teat at 6 hr, had adequate 48 h total serum immunoglobulin levels.  相似文献   

8.
A postal survey of worming practices on West Country dairy farms was undertaken and farmers were requested to send faecal samples for nematode egg counts. The majority of the farmers who responded had a nematode control policy which was based on a mixture of anthelmintics and pasture rotation. Sixty-five per cent turned out calves on to the same paddock each year and 57 per cent treated their stock with anthelmintics during the second year. Ninety farms submitted samples for analysis but only 16 samples contained sufficient eggs to justify repeat egg counts and only eight of these produced enough eggs for in vitro tests. The small number of positive samples, even into the latter part of the year suggests a heavy use of anthelmintics with relatively clean pasture. One Somerset farm had larvae which developed in high concentrations of ivermectin, and eggs were still being passed after two treatments with ivermectin at the manufacturer's recommended dose seven days apart. Of 100 male nematodes isolated from two of the calves, 88 were Cooperia species and 12 were Nematodirus species. A controlled trial with this isolate in eight Friesian male calves showed a 44 per cent reduction in egg counts at day 7 but no significant reduction in worm burden postmortem. This is the first reported case of ivermectin-resistant Cooperia species in cattle in the United Kingdom.  相似文献   

9.
A prospective epidemiological survey on bovine respiratory syncytial virus (BRSV) infections in calves was carried out on 21 dairy farms during one BRSV epidemic season. Special attention was paid to the role of maternal antibodies. On 15 farms the spread of the virus was demonstrated during the investigation period and on eight farms this was accompanied by an outbreak of acute respiratory disease. Disease seldom occurred in calves younger than two weeks old and the most severe disease was observed in calves from one to three months old. Although maternal antibodies did not effectively prevent the disease, both the incidence and severity of disease were inversely related to the level of specific maternal antibodies. Two serodiagnostic techniques were compared. In calves older than three months from herds with disease outbreaks associated with bovine respiratory syncytial virus the diagnosis was established in 80 per cent of the animals by an increase in IgG titre against BRSV and in 77 per cent by the detection of BRSV specific IgM. In comparison, only 10 per cent of the calves younger than three months were positive by IgG serodiagnosis, and 51 per cent by IgM serodiagnosis. On farms where the spread of the virus was accompanied by an outbreak of clinical disease more calves were present, a higher proportion of the calves was younger than three months, and calves of all ages were more often housed together.  相似文献   

10.
The influence of some husbandry factors on morbidity and mortality was studied in 1996 artificially reared, dairy bred calves over the period from purchase until about six weeks of age. The effects of housing (indoors versus outdoors), penning (individual versus group), breed, time since purchase and season of purchase were examined. The overall mortality rate was approximately 4 per cent and calves were more likely to die if reared in groups outdoors than if reared either singly or in groups indoors. The mortality rate was significantly lower in calves purchased between April and June than at other times of year. Pneumonia was the most common disease symptom (48.3 per cent of calves) with diarrhoea the second most common (14.1 per cent). Neither the type of penning nor housing affected the incidence of pneumonia but diarrhoea was most common in individually penned calves. Case mortality rates for diarrhoeic calves in group pens were higher than for those in single pens and case mortality rates for pneumonia were highest for calves reared in groups outdoors. More than half the cases of pneumonia occurred between one and three weeks after purchase whereas two-thirds of the cases of diarrhoea occurred within the first week after purchase. However, case mortality rates for both conditions appeared to increase with time since purchase.  相似文献   

11.
Economic and reproductive consequences of retained placenta in dairy cattle   总被引:2,自引:0,他引:2  
The financial losses due to retained placenta in Dutch dairy cattle were estimated by using two different methods of calculation. A data-set containing the birth records of 160,188 Meuse-Rhine-Yssel cows provided data on the reproductive performance of cows with and without retained placenta. The fertility of cows after retention of the placenta appeared to be affected. An economic calculation made by adding the losses due to increased calving interval, increased culling rate, loss of milk production and the costs of veterinary treatment and drugs revealed that the total loss due to retained placenta was 471 pounds per year for a 100-cow farm with an average incidence of the condition (6.6 per cent). For a 'problem' farm with a 30 per cent rate, the loss was 2139 pounds per year. A computer farm simulation model, based on a stochastic determination of events, was used to make calculations for circumstances closely resembling those on farms. A 6.6 per cent rate of retained placenta caused a small but significant decrease in net return on labour and management; however, a 30 per cent rate caused highly significant changes. The economic effects of retained placenta were similar in magnitude in herds of high or low productivity and high or low fertility. Sensitivity analysis showed that the greatest financial losses were caused by loss of milk production, followed by the number of animals suffering from complications. The financial losses in herds with an average rate of retained placenta were thus of limited economic importance and therapeutic measures alone should be adequate.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

12.
During the decade to 1999, the incidence of human infections with the zoonotic pathogen verocytotoxin-producing Escherichia coli O157 (VTEC O157) increased in England and Wales. This paper describes the results of a survey of 75 farms to determine the prevalence of faecal excretion of VTEC O157 by cattle, its primary reservoir host, in England and Wales. Faecal samples were collected from 4663 cattle between June and December 1999. The prevalence of excretion by individual cattle was 4.2 per cent (95 per cent confidence interval [CI] 2.0 to 6.4) and 10.3 per cent (95 per cent CI 5.8 to 14.8) among animals in infected herds. The within-herd prevalence on positive farms ranged from 1.1 to 51.4 per cent. At least one positive animal was identified on 29 (38.7 per cent; 95 per cent CI 28.1 to 50.4) of the farms, including dairy, suckler and fattening herds. The prevalence of excretion was least in the calves under two months of age, peaked in the calves aged between two and six months and declined thereafter. The phage types identified most widely were 4, 34 and 2, which were each found on six of the 29 positive farms.  相似文献   

13.
Forty-two dairy calves remained with their dams for two days after birth, and then were removed to a calf rearing shed. Calves were allocated to three groups for the next 14 days, and received twice daily either whole milk, whole milk with a 10 per cent supplement of pooled normal bovine colostrum or whole milk with 10 per cent supplement of colostrum from cows vaccinated with rotavirus. A natural outbreak of diarrhoea occurred, affecting 28 of the 42 calves. Feeding immune colostrum delayed the onset of diarrhoea, and reduced its incidence, duration and severity. Live weight gains were consequently improved. The group fed normal colostrum had diarrhoea intermediate in severity between that of control calves and those fed immune colostrum. The aetiology of the diarrhoea was complex, with calves excreting rotavirus, enteropathogenic Escherichia coli and cryptosporidia.  相似文献   

14.
Digestibility of nutrients was determined in healthy calves and in those with diarrhoea at the age of two and three weeks. The total collection of feces and indigestible marker methods (with Cr2O3) were used. High equality of results and statistically non-significant differences between the method of a total collection of feces and indigestible marker one in the suckling calves (Tab. II) confirm the suitability of using these two methods to determine digestibility. Based on the composition and commercially recommended feeding guide of milk replacer, it is clear that it has lower digestible energy, Zn and Fe intake. Slightly higher digestible crude protein and Mg intake, optimum Ca and P intake, all these values were calculated for 1 kg of live weight (Tab. I). Nutrient contents is responsible for nutrient ratio which is unbalanced and for low contents of digestible energy (76.5 KJ per g of digestible crude protein) instead of recommended values of 100-110 KJ per of digestible crude protein in milk replacer in suckling calves. In six clinically healthy calves fed with milk replacer Laktavit twice a day, an apparent digestibility of organic matter was found to be 95.7 +/- 1.8%, crude protein 93.5 +/- 1.8%, fat 94.5 +/- 1.4%, carbohydrates 97.2 +/- 1.5%, Ca absorption was 86.5 +/- 2.8%, P 95.3 +/- 2.9%. There was a depressed absorption for Mg 43.4 +/- 6.8%, Fe 24.2 +/- 4.3% and Zn 36.8 +/- 3.5% (Tab. III).(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

15.
Daily feed rations, their nutrient contents and live weight gains were recorded for calves and replacement heifers from birth to calving in 122 Swedish dairy herds. Preweaned calves were fed whole milk (45% of the herds), milk replacer alone or milk replacer combined with whole milk. Calf starters were the most frequently used concentrates for preweaned calves, whereas grain dominated for weaned calves and heifers. Grain was supplemented with protein concentrates until 6 months of age and at calving. Grass/clover hay was the dominant forage for preweaned calves, whereas grass/clover silage alone or in combination with hay was the most common forage for calves and replacement heifers from 6 months of age. Heifers grazed semi-natural grasslands, leys or a combination of semi-natural grasslands and leys in 33, 15 and 52% of the herds, respectively. According to Swedish recommendations, calves in a majority of the herds were fed too low concentrations of crude protein from weaning to 6 months of age and calves were fed too low a metabolizable energy content inadequate for a daily weight gain of 700 g at weaning. Median live weight gain from birth to calving was only 567 g per day. Correct feed ration formulations and strategic grazing management could be means to increase weight gain and hence to decrease rearing costs of calves and replacement heifers in Swedish dairy herds.  相似文献   

16.
Ghrelin action, which stimulates growth hormone (GH) secretion, may alter during the weaning period in calves. Our objective was to compare the effects of intravenous ghrelin injection on plasma GH, insulin and glucose concentrations in calves around the weaning period. Four Holstein bull calves were fed whole milk and allowed free access to solid feeds, and weaned at 7 weeks of age. Measurements were performed at weeks 1, 2, 4, 6, 7, 9, 11 and 13, when calves were intravenously injected with ghrelin (1.0 μg/kg body weight (BW)) through a catheter, and jugular blood samples were obtained temporally relative to the injection time. Estimated digestible energy intake per metabolic BW transiently decreased at week 7 because of low solid intake immediately after weaning, and thereafter gradually increased. Plasma insulin and glucose concentrations were not affected by ghrelin injection at all ages. In contrast, plasma GH concentrations increased with ghrelin injection at all ages. The incremental area of GH at week 7 was greatest and significantly higher compared with weeks 2, 4, 6 and 9. This result suggests that nutrient insufficiency immediately after weaning enhances GH responsiveness to ghrelin.  相似文献   

17.
On a dairy farm, otitis media was diagnosed in 64 suckler calves (21.8%) during a study period of 2 years, and in 10 calves (3.4%) in the third year. The inflammation was unilateral in 63 and bilateral in 11 calves. The affected calves were dull, lacked appetite, were pyrexic and displayed drooping ear or ears and tilted heads with purulent discharge exuding from the external ear canal. Of the affected animals, 56 (87.5%) were aged between 3 and 8 weeks. Morbidity was higher during the calving season and during the autumn and winter months (October-December). Pasteurella haemolytica was isolated from 21 (32.8%), P. multocida from 20 (31.2%), Actinomyces pyogenes from 11 (17.2%) and Streptococcus pneumoniae from three (4.7%) of the clinically affected calves only during the first two study years. The exudate of the acute ear infections contained, in addition to Pasteurella spp., various bacteria and yeasts. Most of these bacteria were isolated from healthy ears as well, and are likely to be part of the normal ear flora. On the other hand most of the yeasts were isolated from otitic calves. After a short course of an appropriate treatment infections healed in all cases. Possible preventive measures are discussed.  相似文献   

18.
Information on the occurrence and diversity of coccidia infecting cattle in different farming systems in South Africa is lacking. The objective of the study was to determine the levels of infection of coccidia in cattle at three localities and to determine the Eimeria species occurring at each locality. Faecal samples (n=1936) were collected over a 13-month period from a dairy farm (Mallesons), a Bonsmara breeding farm (Kaalplaas) and a Nguni stud farm (Pienaars River). Samples were collected from adults >24 months old and calves <12 months old. The modified McMaster technique was used to determine OPG (oocysts per gram) of faeces. Samples with OPGs > or =2000 were allowed to sporulate in potassium dichromate solution at room temperature. Species identification was done by measurement and morphological characteristic of each species. At Mallesons, 29% of samples were positive, at Kaalplaas 50% and at Pienaars River 52%. The most prevalent species were Eimeria zuernii and E. ellipsoidalis at Mallesons, E. zuernii and E. bovis at Kaalplaas and E. bovis and E. zuernii at Pienaars River, respectively. Adults had very low OPGs. There was a pattern at the three localities in that high OPGs were only recorded in calves, which were also shedding the most pathogenic species.  相似文献   

19.
2009年2月~6月我国某奶牛场发生严重的犊牛多发性关节炎,发病犊牛的症状与最早发生于澳大利亚的犊牛Leachii支原体关节炎非常相似。为确定病原,我们无菌采集2份具有典型症状犊牛的关节液样品进行实验室诊断,2份样品中均检测和分离出支原体。将2个分离菌株的16S rRNA基因和LppA基因与参考支原体菌株进行核苷酸序列比对,发现这2株支原体的16S rRNA基因和LppA基因均与Leachii支原体具有最高的核苷酸序列同源性,分别为99.9%和99.6%。结果显示,本研究分离的2株支原体为Leachii支原体,分别命名为GN407和GN408。综合分析发病犊牛的临床病理学观察和关节液样品的实验室诊断结果,我们确定Leachii支原体为该奶牛场犊牛多发性关节炎的病因。  相似文献   

20.
A new hereditary disease characterised by renal failure, poor growth and long hooves in Japanese Black cattle (wagyu) has been recognised in a region of central Japan since 1990. The number of calves affected has increased gradually, with the incidence reaching 17 of 485 (3.51 per cent) in 1995. Almost all the calves were slightly undersized at birth, and repeatedly had diarrhoea during the neonatal period. They began to show signs of growth retardation with proportional body and elongation of the hooves from about two to five months of age, but they had an almost normal or only slightly decreased appetite. The concentrations of urea nitrogen, creatinine and inorganic phosphorus in serum were high, and the affected calves excreted diluted urine frequently. Among 25 cases, the urine of 21 contained occult blood, 24 contained protein and two contained glucose. In 29 calves observed for 30 to 130 days, the course of the disease varied; in 21 of them it remained unchanged, six became gradually worse and two became severely debilitated and died. The disease was diagnosed as renal tubular dysplasia by histopathological examination.  相似文献   

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