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1.
The frequency of Bordetella bronchiseptica infection in Nebraska specific-pathogen-free (SPF) pigs was determined by serologic and bacteriologic cultural analysis. Serum samples from non-SPF herds were tested for comparison. A total of 1,282 of 1,397 (92%) of the SPF pigs tested had antibody to B bronchiseptica; 37 of 220 (17%) were culture-positive, and 67 of 4125 (1.6%) were considered suspicious for atrophic rhinitis during slaughter inspection. A higher percentage of the non-SPF pigs had titers to B bronchiseptica (642 of 659 pigs or 97% of the pigs tested). There was no relationship between the B bronchiseptica antibody titer, the isolation of B bronchiseptica, or the frequency of gross lesions of atrophic rhinitis from pigs within the herd. The serum agglutination test may be a more reliable procedure for determining the herd prevalence of B bronchiseptica than isolation of the organism by cultural methods.  相似文献   

2.
Torque teno virus (TTV) was first isolated from a human hepatitis patient in 1997. TTV was also identified in several animals, including pigs, cattle, sheep, cats and dogs. In this study, we analysed the prevalence of swine TTV genogroups 1 (TTV1) and 2 (TTV2) in Japanese swine populations with suspected post-weaning multisystemic wasting syndrome and porcine respiratory disease by using a nested polymerase chain reaction method. Of 153 serum samples from 16 different herds in Japan, TTV1 was detected in 46 samples (30%), TTV2 in 47 samples (31%) and both in 15 samples (10%). There was no significant difference in the detection rate among geographical regions. The overall prevalence rate of TTV genogroups was significantly lower in ≤30-day-old pigs (11%) compared to that in older age groups (54–82%). These results suggest that swine TTV may be widespread in post-weaning pigs and could play aetiological roles in pig diseases in Japan. This is the first report on the prevalence of swine TTV in Japan.  相似文献   

3.
The aim of this study was to determine the herd prevalence of veal and dairy herds and to identify risk factors for VTEC O157 positive veal herds. The study was based on monitoring data from November 1996 through July 2005 of 1051 dairy herds and 930 veal herds. The herd level prevalence (95% CI) was 8.0% (6.4–9.6) for dairy herds and 12.6% (10.5–14.7) for veal herds. Within the population of veal herds, a prevalence of 39.8% (33.9–45.6) was found for pink veal herds (n = 269) and 1.5% (0.7–2.8) for white veal herds (n = 661).Multivariable logistic regression showed that the type of veal (pink vs. white; OR = 21.6; 95% CI: 10.4–45.0), ventilation (mechanical vs. natural; OR = 0.4; 95% CI: 0.2–0.8), time between arrival in the herd and sampling (3–5 months vs. 0–2 months: OR = 2.33; 95% CI: 1.1–5.1, ≥6 months vs. 0–2 months: OR = 4.11; CI: 1.9–8.9), other feed than the 7 most common (yes vs. no; OR = 2.1; 95% CI: 1.2–3.7) and at least one dog present in the stable (yes vs. no; OR = 2.6; 95% CI: 1.5–4.6) were significantly (P < 0.05) associated with the presence of VTEC O157. The large difference in the VTEC O157 prevalences for pink veal and white veal production might have been caused by a very different management of these type of herds. However, this could not be studied with the data collected.  相似文献   

4.
The prevalence and distribution of seropositivity towards the protozoan parasite Neospora caninum were studied in single blood samples from 1561 cows from 31 Danish dairy herds. Blood samples were analysed by an indirect enzyme-linked immunoassay and an indirect fluorescent-antibody test. Seroprevalence in 15 herds with previous abortions assigned to neosporosis ranged from 1% to 58%, with a mean frequency of 22%. In eight out of 16 herds without a history of N. caninum related abortions, no seroreactors were found. In the remaining eight herds, the seroprevalence ranged from 6% to 59%. The prevalence and distribution of seropositivity, gestation number prior to sampling, and breed were related to abortions and perinatal deaths using a random-effects logistic-regression model. Abortion risk was significantly increased in seropositive animals (OR=3) and in 2nd-gestation cows (OR=3). Perinatal death was significantly influenced by gestation number and breed, but not by serostatus. Reproductive performance and culling risk of cows were not affected by serostatus. Seropositivity increased with “age” (i.e. gestation number) (P=0.02). In open cows, seropositivity tended to decrease with distance from calving (P=0.05). The proportion of seropositive pregnant cows increased with trimester (P=0.02).  相似文献   

5.
The epidemiologies of the most common diseases diagnosed in pigs at the Danish pig-breeding test stations were studied. In this article (one of three), the material and disease incidence are described. The population under study comprised 9 084 test pigs (corresponding to 3 028 test groups) housed at nine test stations from September 1983 to September 1984. Five stations housed groups from conventional herds and four stations groups from specific-pathogen-free (SPF) herds. The average incidence of respiratory disease at the conventional stations was 41.1%, but great variations existed between the stations (from 19.4% to 74.9%). The incidence of respiratory disease at the SPF stations varied from 0.2% to 24.8% (average 18.7%). The incidence of diarrhoea was 4.0% in the conventional system and 7.7% in the SPF system. The frequency of pigs culled because of disease was 7.6% at the conventional stations (range 2.2%–10.8%) and 2.0% at the SPF stations (range 0.9%–3.6%). Very low rates of mortality were found. The prevalence of pathological findings at slaughter (pneumonia and pleurisy) was lower for the test pigs than for total pigs slaughtered at the same abattoir in the same period (especially for the SPF system).  相似文献   

6.
As Specific Pathogen‐Free (SPF) pig herds are designed and managed to prevent specific pig diseases, it might be feasible to expand the list of micro‐organisms also including zoonotic pathogens such as Campylobacter coli as this agent has its origin in pigs. In a previous survey, 15 of 16 of SPF herds were found free from human pathogenic Yersinia enterocolitica. Accordingly, three nucleus and seven multiplying herds were surveyed for Campylobacter to investigate whether the Norwegian SPF pig pyramid also might be free from this agent. In conclusion, the intervention of Campylobacter at the herd level might be possible as four of 10 SPF herds tested negative in two sets of samples from both autumn 2008 and summer/early autumn 2010. The four negative herds were all located in remote areas several kilometres away from conventional pig farming while the positive SPF farms were all situated in neighbourhoods with conventional pig production. It seems more difficult to control Campylobacter than some specific animal disease agents and another significant zoonotic agent, Y. enterocolitica, in pig herds.  相似文献   

7.
Summary Sera from 683 pigs of 41 swine herds with clinical atrophic rhinitis (A R), from 477 pigs of 37 herds with no A R history, from 267 breeding sows and breeding boars for slaughtering, from 22 boars at an artifical insemination centre, and from 103 SPF pigs were tested for the presence of antibodies to porcine cytomegalo virus (PCMV). The herds examined were spread all over the Netherlands. For the presence of antibodies to PCM V the indirect fluorescence antibody test was used. To obtain the antigen, the PCMV had been grown in pig lung macrophage cultures in Petri dishes for 10-12 days. These macrophages were dropped into the wells of slides. The serum dilution 1:20 of all the 103 sera from SPF pigs were negative, but 93 per cent of the other sera were positive. No marked differences were found between swine herds with clinical atrophic rhinitis and herds with no A R history. The FA titres in both types of herds seem to be at a comparable level.  相似文献   

8.
The development of circulating antibodies for H. parahaemolyticus was studied in experimentally infected SPF pigs and in-contact SPF pigs. Blood serum titers were determined by a modified complement fixation test with normal SPF swine serum as a source of supplementary complement factor, and by an indirect haemagglutination test.CF and IHA titers became positive within the first 2 weeks following exposure to H. parahaemolyticus, and reached peak values after 2 to 7 weeks (Figs. 1 to 3). The exposed pigs proved immune, in that they showed no clinical symptoms on challenge after resp. 6, 9 and 11 weeks.While distinct titers were thus obtained with both tests in SPF swine experimentally exposed to H. parahaemolyticus, the CF test proved more specific than the IHA test when the 2 tests were compared in a field outbreak of polyserositis (Glässers disease) caused by H. parasuis. The CF test would therefore seem to be preferable to the IHA test in field diagnostic work (Table 1).A noticeable finding was that challenge did not elicit an anamnestic antibody response in any of the immune pigs (Figs. 1 to 3). This fact together with negative bacteriological findings in the animals in question would seem to suggest that the challenge dose was unable to establish a permanent infection in the respiratory tract of the immune pigs.  相似文献   

9.
To facilitate the control of enzootic pneumonia (EP) of swine caused by Mycoplasma hyopneumoniae, the complement fixation (CF) test has been used for the detection of M. hyopneumoniae antibodies. However, the CF test is a cumbersome and time-consuming technique and cross-reactivity are major drawbacks associated with this method. To circumvent these drawbacks, we have developed a double-sandwich enzyme-linked immunosorbent assay (ELISA), consisting of purified monoclonal antibody (Mab) against the 46 kDa surface antigen (P46) of M. hyopneumoniae and recombinant P46 protein expressed in Escherichia coli, for the detection of antibodies to M. hyopneumoniae in serum samples from pigs experimentally inoculated with M. hyopneumoniae and from naturally infected pigs, and compared the practical usefulness of ELISA using the CF test. In experimentally inoculated pigs, the CF and ELISA antibodies were detected at almost the same time, and a good correlation was demonstrated between the CF test and the ELISA. In a survey conducted on field samples, the seropositivity by ELISA in pigs of age 2-6 months was increased. At the time of slaughter, approximately 80% of the animals were seropositive for ELISA. However, a gradual decrease in the prevalence of ELISA positive samples was observed in sows with increasing parity. No correlation was seen between the results obtained with the two methods in the clinical samples. The CF test appears to have limited value for the diagnosis of EP in conventional herds because nonspecific reactions were frequently observed. Therefore, this ELISA is a useful alternative to the CF test currently used for the diagnosis of EP.  相似文献   

10.
Glasser's disease accounted for less than 1% of total swine mortalities in an 11 year retrospective postmortem survey of swine submissions at three provincial government diagnostic laboratories in southern Ontario. However, Glasser's disease was suspected in 17 of 83 boar mortalities at the Record of Production Boar Test Station between 1983 and 1985 and was much more common in specific-pathogen-free (SPF) boars than in conventional boars. The prevalence of the causative organism, Haemophilus parasuis, was determined for 19 SPF herds in Ontario classified as "Excellent" under the Ontario Swine Herd Health Policy. Nasal swabs from two-month-old pigs were cultured on chocolate agar containing 1.5 mug/mL lincomycin, 5 mug/mL bacitracin, and 0.1 mug/mL crystal violet. Three herds were negative for H. parasuis infection; 16 herds contained clinically healthy carrier pigs.  相似文献   

11.
A total of 407 swine bred in south-eastern Norway have been tested for the presence of Toxoplasma gondii antibodies in serum by use of the dye-test, and diaphragm muscle from all sero-positive and some sero-negative swine has been tested for the presence of mouse-infective cysts.The prevalence of antibodies was as low as 10.1 %. The prevalence increased with the weight of the swine, but apparently with a decline after passing a weight of 140 kg. Only dye-test titres up to 50 were found. The prevalence of dye-test positive swine was higher in small herds (< 300 swine p.a.) than in larger ones (> 300 swine p.a.). The prevalence of herds with dye-test positive swine in the region surrounding the Oslo-fjord was higher in the coastal than in the inland zone. The incidence of infection was the same during the summer-autumn period as during the winter-spring period. Toxoplasma was recovered from the diaphragm muscle of about % of the dyeπtest positive swine. Parasites were isolated from some pigs with a dye-test titre of 4, and from all the pigs with a titre of 50. Toxoplasma was not isolated from dye-test negative swine. The epidemiological and food-hygienic significance of porcine toxoplasmosis in Norway is discussed according to the present results.  相似文献   

12.
Cryptosporidium parvum is a protozoan parasite causing diarrhoea in young calves. This cross-sectional study was performed to estimate the prevalence of Cryptosporidium infected herds in a sample of Swedish dairy herds and to identify potential risk factors associated with shedding of oocysts. Fifty dairy herds, selected by stratified random sampling, were included. The herds were visited once during the indoor seasons of 2005–2006 and 2006–2007. Faecal samples were collected from 10 calves, 10 young stock and 5 cows in each herd. Clinical observations of sampled animals and environmental status were recorded, and farmers were interviewed about management procedures. Faecal samples were cleaned by sodium chloride flotation and detection of oocysts was made by epifluorescence microscopy. Cryptosporidium parvum-like oocysts were found in 96% of the herds. Prevalence was 52% in calves, 29% in young stock and 5.6% in cows. Three two-day-old calves shed oocysts. Cryptosporidium andersoni was found in seven animals from four different herds. Factors associated with prevalence of shedders among sampled animals in a herd were age at weaning, cleaning of single calf pens, placing of young stock, system for moving young stock, and year of sampling. Factors associated with shedding in calves were age, placing of young stock, routines for moving young stock and time calf stays with the cow. The only significant factor in young stock was age. In cows, number of calves in the herd and type of farming (organic vs. conventional) affected shedding.  相似文献   

13.
A nation-wide Salmonella enterica surveillance and control programme was initiated in Danish finishing herds over the first quarter of 1995. In Denmark, all swine for slaughter are identifiable by a unique herd code. For each herd code, and depending on the herd's annual kill, random samples ranging from four to more than 60 swine are obtained quarterly at the abattoir. A meat sample from each pig is frozen, and meat juice (harvested after thawing) is examined for specific antibodies against S. enterica using an indirect enzyme-linked immunosorbent assay (ELISA). The ELISA combines several S. enterica O-antigens, and allows detection of antibody response after a variety of different S. enterica serovar infections. Results are transferred to a central database, which each month (based on meat-juice tests obtained in the previous 13 weeks) assigns all herds into three S. enterica infection levels: Level 1, in which the S. enterica prevalence is deemed low and acceptable; Level 2, where there is a moderate prevalence of S. enterica seroreacl.ors (from > 50% in the smallest to > 10% in the largest herds); Level 3, in which S. enterica seroreactor prevalence is clearly unsatisfactory ( > 50% for most herd sizes). Irrespective of Salmonella level, all herds receive a monthly update on the current results of the S. enterica test results. If a herd is categorized in Level 2 or 3, it must receive an advisory visit by a practising veterinarian and a local swine extension specialist, and certain management hygiene precautions must be taken. If a herd is categorized in Level 3, the finishers from the herd must additionally be slaughtered under special hygiene precautions. This is supervised by the veterinary authorities.

During 1995, 604000 samples were tested for S. enterica, corresponding to 3.0% of the total kill. In December 1995, 15522 herds (representing > 90% of the national production) were categorized into one of the three levels: 14551 herds (93.7%) in Level 1; 610 herds (3.9%) in Level 2; 361 herds (2.3%) in Level 3. The proportion of serologically positive meat-juice samples collected during 1995 ranged from a mean of 2.9% in smaller herds (101–200 swine slaughtered per year) to 6.1% in relatively large herds (more than 5000 swine slaughtered per year).  相似文献   


14.
The objectives of this study were to investigate the risk factors of Neospora caninum infection in dogs and cats found in dairy herds in western Thailand. A case-control study was conducted in dairy herds in three western provinces including Nakhon Pathom, Ratchaburi and Kanchanaburi. Blood samples of pets from 14 positive dairy herds and 26 herds from negative neighbouring farms which were randomly selected, in total blood samples from dogs and cats from 40 herds were collected and examined for antibodies against N. caninum infections using competitive ELISA and indirect fluorescent antibody test (IFAT). No seropositive cats were found. Of the 38 positive dogs, four (10.5%) were seropositive to N. caninum, which was higher than the proportion of seropositive in the negative herd population (one of 76, 1.3%). The higher proportion of seropositive farm dogs as compared with neighbouring dogs tended to be significant (P = 0.055).  相似文献   

15.
The objective of this study is the detection of Mycobacterium avium subsp. paratuberculosis (MAP) by serum enzyme-linked immunosorbent assay (ELISA), fecal polymerase chain reaction (PCR), and fecal culture in Colombian dairy herds. Serum and fecal samples from asymptomatic cows (n = 307) of 14 dairy herds were tested for MAP by an unabsorbed ELISA test (ELISA-A). Serum and fecal samples from positive ELISA-A animals (n = 31) were further tested by an absorbed ELISA test (ELISA-B) and PCR. Fecal samples from animals of herds positive by ELISA-A and PCR (n = 105) were inoculated onto three different culture media. ELISA-A produced positive results in 10% of the serum samples and 71% of the herds. ELISA-B and PCR results were positive in two and six serum and fecal samples from positive ELISA-A animals, respectively. Fecal samples were negative for MAP on all culture media. The results of this study confirmed the presence of MAP in local dairy herds and the difficulties of MAP detection in asymptomatic animals by ELISA, PCR, and fecal culture.  相似文献   

16.
Calves following an enhanced-growth feeding program usually show lower starter intakes during the preweaning period compared with conventionally-fed calves. To assess whether this low intake in calves following an enhanced-growth feeding program affects calf capacity to digest starter after weaning, 19 Holstein male calves were used to measure apparent nutrient digestibility at weaning. Calves were divided in two groups: calves on a conventional feeding program (CF) and calves on an enhanced-growth feeding program (EF). After one week of adaptation to milk replacer (25% CP and 19% fat), the CF calves were fed 4 l/d of milk replacer (MR) at 12.5% DM dilution rate from d 1–28, and 2 l/d from d 29 to weaning day at d 35, and the EF calves were offered MR at 18% DM dilution rate: 4 l/d from d 1–6, 6 l/d from d 7–13, 7 l/d from d 14–20, 6 l/d from d 21–28, and 3 l/d from d 29 to 35. Calf starter (20% CP) was offered ad libitum from the beginning to the end of study at d 42, and its consumption was recorded daily. Calves were weighed at d 3, 17, 24, 31, 38 and 42. Daily total faeces collection was conducted for the last 5 d of study. Final BW was numerically greater in EF than in CF calves (88.6 vs 81.2 ± 3.36 kg, respectively). Starter DMI was greater (P < 0.05) in CF compared with EF calves during the preweaning (0.68 vs 0.36 ± 0.078 kg/d, respectively) and postweaning (2.52 vs 1.90 ± 0.102 kg/d, respectively) periods, but there were no differences in total DMI (1.12 and 1.26 ± 0.078 kg/d, in CF and EF calves, respectively) during the preweaning period. However, apparent DM, OM, NDF, CP, and GE digestibility coefficients were greater (P < 0.05) in CF compared with EF calves (77.4 vs 71.8 ± 1.23%, 78.7 vs 73.2 ± 1.18%, 34.7 vs 20.3 ± 3.79%, 77.1 vs 71.6 ± 1.29%, and 75.6 vs 69.8 ± 1.25%, respectively) the week after weaning. It is concluded that calves in the EF treatment presented lower nutrient digestibility coefficients compared with CF calves the week after weaning.  相似文献   

17.
Anellovirus is a recently created, floating genus of viruses. Torque teno virus (TTV), the type species in the genus, was first discovered in a human patient with a post-transfusion hepatitis of unknown aetiology. Recently, TTV genetically related to but distinct from those discovered in humans have also been found in animals, including pigs. The aims of this study were to estimate the prevalence of swine TTV in Italian pig herds and some risk factors possibly associated with this infection. Serum samples from 179 healthy pigs from 10 farms located in north-central Italy were tested by polymerase chain reaction for the presence of swine TTV DNA. Viral DNA was found in the sera of 43 pigs (24.0%), coming from eight of the 10 farms examined. Prevalence was significantly higher in finishing herds (40.1%) than in farrow-to-finish herds (11.0%) and did not depend on the size of the herd. Within the finishing herds the prevalence was significantly higher in weaners (57.4%) than in fatteners (22.9%), but this difference was not observed in farrow-to-finish herds. No relationship was observed between the prevalence of swine TTV and the implementation of some general hygiene practices and biosecurity procedures within the herds.  相似文献   

18.
Sera from swine experimentally or naturally infected with Mycoplasma hyopneumoniae (the etiological agent of mycoplasmal pneumonia of swine, MPS) were tested by the indirect hemagglutination assay (IHA), the enzyme-linked immunosorbent assay (ELISA) and the complement fixation (CF) test. The IHA detected antibody at comparable times and levels to the other 2 serological tests following experimentally-induced infection. In the late antibody response (greater than or equal to 86 days post-infection), the ELISA titres were higher than either the IHA or the CF test. The IHA appeared least satisfactory when it was used to test sera from commercial swine herds. When 1000 sera were tested, the IHA was positive for only 30 (22%) of 135 sera which were positive by the ELISA and the CF test. The IHA titres were low; 20 of the 30 sera had a titre of only 10. The end-points for the IHA were difficult to read for sera of this low titre. The relationship between positive IHA results for the herd sera obtained at necropsy, and the occurrence of gross or microscopic lesions typical of MPS was poor (41 and 50% agreement, respectively). An agreement of 39% was noted between positive IHA results and the localization of mycoplasmal antigens by an indirect immunofluorescence (IIF) test. However, IHA results correlated significantly (P less than 0.05) with gross and microscopic lesions, but not with the IIF test. No significant correlation was noted between the IHA (or the other 2 serologic tests) and the cultural isolation of M. hyopneumoniae or M. flocculare. On the basis of these results, the IHA appears to have limited promise as a practical test for the diagnosis of MPS in commercial swine herds because of the low titres observed, poor correlation of the IHA and other indicators of MPS, the necessarily subjective determination of end-points, and other inherent technical limitations of the test.  相似文献   

19.
The presence of antibodies against Encephalitozoon cuniculi (E. cuniculi) and Encephalitozoon intestinalis (E. intestinalis) was examined in 215 samples from humans and in 488 samples from five different species of domestic and companion animals in Slovakia. The 215 human samples and samples from 90 swine, 123 non-infected cattle (cattle), 24 cattle infected with bovine leukosis virus (BLV-positive cattle), 140 sheep and 111 dogs were examined by the enzyme-linked immunosorbent assay (ELISA). Samples with serum titres 1:200 or higher were considered as positive. Specific anti-E. cuniculi antibodies were found in humans (0.9%), swine (52%), cattle (2%), sheep (9%) and dogs (15%) except for the BLV-positive cattle at the titre of 1:200. The titre of 1:400 was detected only in humans (0.5%). The presence of specific anti-E. intestinalis antibodies at the titre of 1:200 was confirmed in humans (6%), swine (51%), cattle (11%), BLV-positive cattle (13%) and dogs (6%) but not in sheep. The anti-E. intestinalis antibodies reached the 1:400 in humans (1%), swine (4%) and BLV-positive cattle (17%). The presence of specific anti-E. intestinalis antibodies at the titre of 1:600 was observed only in one swine (1%). Significant differences were observed in animals at titres 1:200 and 1:400 (chi-squared test: p < 0.0001) for both pathogens and in humans only for E. cuniculi at the titre of 1:400 (chi-squared test: p < 0.0075).  相似文献   

20.
The objective of the study was to estimate the range of influence between cattle herds with positive Salmonella Dublin herd status. Herd status was a binary outcome of high/low antibody levels to Salmonella Dublin in bulk-tank milk and blood samples collected from all cattle herds in Denmark for surveillance purposes. Two methods were used. Initially, a spatial generalised linear mixed model was developed with an exponential correlation function to estimate the range of influence simultaneously with the effect of potential risk factors. An iteratively reweighted generalised least squares procedure was used as a second method for verifying the range of influence estimates. With this iterative procedure, deviance residuals were calculated based on a generalised linear model and the range of influence was estimated based on the residuals using an exponential semivariogram. The range of influence was estimated for six different regions in Denmark using both methods. The analyses were performed on data collected during 1 year after initiation of the Salmonella Dublin surveillance program providing herd classifications for the 4th year-quarter of 2003 and 2 years later for the 4th year-quarter of 2005. The prevalence of dairy herds with a positive Salmonella Dublin herd classification status in this period had decreased from 22.1 to 17.0%. In non-dairy herds, the prevalence was nearly unchanged during the same period (3.4 and 3.7% in 4th quarter of 2003 and 2005, respectively). For all cattle herds, the range of influence was 2.3–6.4 km in 2003 and 1.5–8.3 km in 2005. There seemed to be no association between the range of influence and the density of herds in the different regions.  相似文献   

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