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1.
The purpose of this report is to validate a new protocol, the thermo-assisted drying and decontamination (TADD) system, for eliminating porcine reproductive and respiratory syndrome virus (PRRSV) from contaminated transport vehicles. Scale models of weaned pig trailers were used. The principle of TADD is to raise the interior temperature of trailers to 71 degrees C for 30 min to promote drying and degradation of PRRSV. Trailer interiors were artificially contaminated with 5 x 10(5) TCID50 of PRRSV strain MN 30-100, then treated with 1 of 4 treatments: 1) TADD; 2) air only (no supplemental heat); 3) overnight (8 h) drying; and 4) washing only. Following treatment, swabs were collected from the trailer interiors at 0, 10, 20, and 30 min post-treatment and from the overnight group after 8 h. Swabs were tested for PRRSV-RNA by polymerase chain reaction (PCR). As a measure of the presence of infectious PRRSV, sentinel pigs were housed in treated trailers for 2 h post-treatment and supernatants from swabs were injected IM into naive pigs (bioassay), the recipient pigs were then tested for PRRSV infection. All trailers were PRRSV positive by PCR immediately after washing, prior to treatment (pt). At 10 min pt, 7/10 swabs were positive from the TADD trailers; however, all swabs collected at 20 and 30 min pt were PRRSV negative by PCR, and trailer interiors were visibly dry. In contrast, 9/19, 6/10, and 6/10 swabs collected at 10, 20, and 30 min, respectively, from trailers treated with air only were positive and visibly wet. All swabs (10/10) collected from trailers treated with washing only were PRRSV positive by PCR and all swabs collected at 8 h of drying were PRRSV negative by PCR. All tests for the presence of infectious PRRSV were negative for trailers treated with TADD and overnight drying, while infectious PRRSV was detected in sentinel pigs and bioassay pigs in the other groups. Under the conditions of this study, the efficacy of the TADD system was equal to that of the overnight drying treatment, and it required a shorter period of time to complete its objective.  相似文献   

2.
The objective of this study was to evaluate the efficacy of commercially available disinfectants to sanitize porcine reproductive and respiratory syndrome virus (PRRSV) contaminated trailer models in cold climates (-20 degrees C and 4 degrees C). Disinfectants evaluated included Synergize, Aseptol 2000, Biophene, Sentramax, Virkon, Tek Trol, and DC&R. All products were applied to trailers via fumigation at 4 degrees C. Following experimental contamination of model trailers with PRRSV MN 30-100 (5 x 10(5) TCID50), models were tested for the presence or absence of PRRSV-RNA by polymerase chain reaction (PCR) on swabs collected 0, 30, and 60 min after treatment. Treatments included washing only, washing plus disinfectant fumigation, washing plus fumigation, and washing plus overnight drying. The PRRSV-RNA detected across trailers ranged from 0/12 replicates in trailers treated with Synergize or allowed to dry for 8 h. These trailers were also negative for the presence of infectious PRRSV, based on the lack of sentinel pig infection (0/4 replicates). In contrast, the detection of PRRSV-positive swabs by PCR ranged from 3/12 (Aseptol) to 10/12 (Biophene). Based on these results, the efficacy of Synergize was evaluated at -20 degrees C. In an attempt to reduce the impact of freezing on disinfectant activity, 30 mL of disinfectant was added to a 3840 mL of a 40% methanol solution, a 10% propylene glycol (PG) solution, or water alone. The PRRSV-contaminated trailers were treated with 1 of 3 disinfectant mixtures via fumigation, stored for 8 h at -20 degrees C, allowed to thaw, and sampled as described. Trailers treated with 40% methanol or 10% PG did not freeze and were negative for PRRSV-RNA and infectious virus following thawing. In contrast, trailers treated with disinfectant and water were frozen within 60 min at -20 degrees C, and decontamination was not successful.  相似文献   

3.
The objectives of this study were to determine the concentration of porcine reproductive and respiratory syndrome virus (PRRSV) in a scale-model trailer that was required to infect susceptible pigs, evaluate the potential of PRRSV-contaminated transport vehicles to infect na?ve pigs and assess 4 sanitation programs for the prevention of virus spread. To maximize study power, scale models (1:150) of weaned-pig trailers were constructed that provided an animal density equal to that of an actual weaned-pig trailer capable of transporting 300 pigs. The 1st aim involved contaminating the interior of the model trailers with various concentrations (10(1) to 10(4) TCID50/mL) of PRRSV MN 30-100, then housing sentinel pigs in the trailers for 2 h. Pigs exposed to trailers contaminated with > or = 10(3) TCID50/mL became infected. The 2nd aim involved housing experimentally infected seeder pigs in trailers for 2 h, then directly introducing sentinel pigs for 2 h. Infection of sentinels was demonstrated in 3 of 4 replicates. The 3rd aim involved applying 1 of 4 sanitation procedures (treatments) to contaminated trailers. Treatment 1 consisted of manual scraping of the interior to remove soiled bedding (wood chips). Treatment 2 consisted of bedding removal, washing (80 degrees C, 20,500 kPa), and disinfecting (with 1:256 phenol; 10-min contact time). Treatment 3 consisted of treatment 2, followed by freezing and thawing. Treatment 4 consisted of bedding removal, washing, disinfecting, and drying. Ten replicates were conducted per treatment. Pretreatment swabs from all trailers tested positive by polymerase chain reaction (PCR). Post-treatment swabs were PCR-positive for all trailers except those that were washed, disinfected, and dried. Infection of sentinel pigs by PRRSV was also detected by PCR after all treatments except washing, disinfecting, and drying. Under the conditions of this study, drying appeared to be an important component of a sanitation program for ensuring PRRSV biosecurity of transport vehicles.  相似文献   

4.
To evaluate the transmission of Mycoplasma hyopneumoniae and porcine reproductive and respiratory syndrome virus (PRRSV) by aerosol as either a single or mixed infection, 28 pigs were inoculated intratracheally with M hyopneumoniae on day 0 and infected intranasally with PRRSV on day 35; they were housed together in a barn. To assess the aerosol transmission of M hyopneumoniae as a single infection, one trailer (A) containing 10 five-week-old sentinel pigs was placed along the south side of the infected barn (1 m from the fans) on day 28. To assess the mixed infection, two trailers (B and C), each containing 10 five-week-old sentinel pigs, were placed along each side of the barn on day 42. The sentinel pigs in the three trailers were exposed to the exhaust from the fans for seven days. No M hyopneumoniae infection was detected in the sentinel pigs in trailer A, but it was detected in the sentinel pigs in trailers B and C. No PRRSV was detected in any of the sentinel pigs.  相似文献   

5.
The aim of this study was to determine whether porcine reproductive and respiratory syndrome virus (PRRSV) could be transmitted by aerosol under field conditions. A total of 210 five-month-old PRRSV-negative pigs were housed in a mechanically ventilated finishing facility containing 11 pens. Pen 1 contained 10 pigs (indirect contact controls) and pen 2 remained empty, providing a barrier of 2.5 m from the remaining pigs in pens 3 to 11. Fifteen or 16 of the pigs in each of pens 3 to 11 were infected experimentally with a field isolate of PRRSV and the other six or seven pigs served as direct contact controls. Five days after the pigs were infected, two trailers containing 10 five-week-old PRRSV-naive sentinel pigs were placed along each side of the building; one was placed 1 m from the exhaust fans on one side of the building, and the other was placed 30 m from the fans on the other side, and the sentinel pigs remained in the trailers for 72 hours. They were then moved to separate buildings on the same site, 30 and 80 m, respectively, from the infected barn, and their PRRSV status was monitored for 21 days. The direct and indirect contact control pigs became infected with PRRSV but the sentinel pigs did not.  相似文献   

6.
An experimental infection with porcine reproductive and respiratory syndrome virus (PRRSV) was established in 150 five-month-old pigs housed in a fan-ventilated finishing facility, the infected barn. To determine whether air exhausted from the wall fans contained infectious PRRSV, a trailer containing 10 four-week-old PRRSV-naive sentinel pigs was placed 10 m from the building from day 3 after the 150 pigs were infected until day 10. To connect the two airspaces, one end of an opaque plastic tube, 15 m in length and 5 cm in diameter, was fastened to the wall fan of the infected barn, and the other end was placed inside the trailer. Air from the building was exhausted into the trailer 24 hours a day for seven consecutive days and PRRSV infection was monitored in the infected pigs and the sentinel pigs. Air samples were collected from the infected barn and the trailer. PRRSV infection was detected in the infected pigs three and seven days after they were infected, but not in the sentinel pigs. All the air samples were negative for PRRSV by PCR, virus isolation and a pig bioassay.  相似文献   

7.
To assess the transmission of porcine reproductive and respiratory syndrome virus (PRRSV) from pigs to mallard ducks, 10 adult (one-year-old) female mallard ducks were housed with pigs infected experimentally with PRRSV, and allowed to be in close contact with them for 21 days. To evaluate the transmission of PRRSV from mallard ducks to pigs, two adult ducks were inoculated orally with PRRSV (total dose 10(6.0) TCID50) and allowed to drink PRRsv-infected water; 24 hours later, two four-week-old PRRsv-naive sentinel pigs were housed in pens below the cages housing the ducks for 14 days. In both experiments, cloacal and faecal samples were collected three times a week from the ducks and tested by PCR, virus isolation and a pig bioassay. Blood samples from the pigs were tested by ELISA, PCR and virus isolation. Sera from the ducks were tested by serum neutralisation. The ducks were examined postmortem and selected tissues were tested by PCR, virus isolation, histopathology and pig bioassay. In both experiments all the cloacal swabs, faecal samples, tissues and sera from the ducks were negative by all the tests. The sera from the pigs in the first experiment were PCR positive at three, seven, 14 and 21 days after infection and ELISA positive at 14 and 21 days. Sera from the pigs in the second experiment were negative by all the tests. The virus was isolated from the oral inoculum and the drinking water provided for the ducks in the second experiment. Under the conditions of this study, it was not possible to demonstrate the transmission of PRRSV either from the pigs to the ducks or from the ducks to the pigs.  相似文献   

8.
The objective of this study was to determine whether porcine reproductive and respiratory syndrome virus (PRRSV) could be transmitted to naïve pigs by mosquitoes following feeding on infected pigs. During each of 4 replicates, mosquito-to-pig contact took place on days 5, 6, and 7 after PRRSV infection of the donor pig. A total of 300 mosquitoes [Aedes vexans (Meigen)] were allowed to feed on each viremic donor pig, housed in an isolation room. After 30 to 60 s, feeding was interrupted, and the mosquitoes were manually transferred in small plastic vials and allowed to feed to repletion on a naïve recipient pig housed in another isolation room. Prior to contact with the recipient pig, the mosquitoes were transferred to clean vials. Swabs were collected from the exterior surface of all vials, pooled, and tested for PRRSV. Separate personnel handled the donor pig, the recipient pig, and the vial-transfer procedure. Transmission of PRRSV from the donor to the recipient pig occurred in 2 out of 4 replicates. The PRRSV isolated from the infected recipient pigs was nucleic-acid-sequenced and found to be 100% homologous with the virus used to infect the donor pigs. Homogenates of mosquito tissues collected in all replicates were positive by either polymerase chain reaction or swine bioassay. All control pigs remained PRRSV negative, and PRRSV was not detected on the surface of the vials. This study indicates that mosquitoes (A. vexans) can serve as mechanical vectors of PRRSV.  相似文献   

9.
Porcine reproductive and respiratory syndrome virus (PRRSV) is an RNA virus in the order Nidovirales, family Arteriviridae, genus Arterivirus. The virus induces a prolonged viremia, replicates in macrophages, and produces persistent infection. The purpose of this study was to determine if PRRSV could persist for 90 d or more in a large population of breeding-age gilts housed under environmental conditions typical of commercial swine production and to determine if experimentally infected gilts could shed virus to naïve sentinel gilts beyond 90 d postinfection. Using the intranasal route, we inoculated 120 PRRSV-naïve gilts, 4 mo of age, with 5 mL of cell culture fluid containing a total dose of 102.4 TCID50 of a field isolate (MN-30100) of PRRSV. The index gilts were organized into 3 groups (A, B, and C), 40 gilts per group. To assess the dynamics of the experimental infection, a monitor group of 30 index gilts was blood-tested on days 0, 3, 7, 14, 30, 60, 90, 120, 150, and 180 postinfection. PRRSV viremia was detected with the polymerase chain reaction (PCR) on days 3, 7, and 14 and by virus isolation (VI) on days 7 and 14. PRRSV antibodies were detected from day 14 by enzyme-linked immunosorbent assay (ELISA). To assess shedding, 30 PRRSV-naïve sentinel gilts were commingled with the index gilts on day 90 postinfection and tested by PCR, VI, and ELISA every 15 d until 180 d postinfection; all samples were negative. To assess persistence, 40 index and 10 sentinel gilts were slaughtered at 120 (group A), 150 (group B), or 180 (group C) d postinfection. Evidence of PRRSV was not detected by PCR or VI in any tissue samples from the 120 index gilts. These results indicate that persistence and shedding of PRRSV are of short duration in breeding-age gilts.  相似文献   

10.
A study was conducted to assess the effect of UV(254) on the concentration and viability of PRRSV on surfaces and materials commonly encountered on swine farms. A standard quantity (5 × 10(6)TCID(50), total dose) of a PRRSV modified live vaccine virus was inoculated onto 2 matched sets of surfaces/materials including wood, plastic, latex, rubber, styrofoam, metal, leather, cloth, concrete, cardboard, glass and paper. One set was exposed to UV(254) radiation (treatments) and the other to incandescent light (controls) for a 24h period. During this time, treatments and controls were swabbed at 10 min intervals from 0 to 60 min post-inoculation (PI) and again at 24h PI. The quantity of PRRSV RNA on each item at each sampling time was calculated by RT-PCR and the presence of viable PRRSV in each sample was determined by swine bioassay. A significant reduction (p<0.0001) in the quantity of PRRSV RNA was demonstrated at 24h PI independent of treatment. In addition, a significant reduction (p=0.012) in the number of UV(254)-treated surfaces which harbored viable virus was observed at 60 min (0/12 positive) when compared to control surfaces (5/12 positive). In addition, all UV(254) treated samples collected between 10 and 50 min PI were bioassay negative. These results suggest that UV(254) is an effective means to inactivate PRRSV on commonly encountered farm surfaces and materials and inactivation can be accomplished following 10 min of exposure.  相似文献   

11.
The purpose of this study was to evaluate the potential for houseflies (Musca domestica) to mechanically transport and transmit porcine reproductive and respiratory syndrome virus (PRRSV) between pig populations under controlled field conditions. The study employed swine housed in commercial livestock facilities and a release-recapture protocol involving marked (ochre-eyed) houseflies. To assess whether transport of PRRSV by insects occurred, ochre-eyed houseflies were released and collected from a facility housing an experimentally PRRSV-inoculated population of pigs (facility A) and collected from a neighboring facility located 120 m to the northwest that housed a naïve pig population (facility B). All samples were tested for PRRSV RNA by polymerase chain reaction (PCR). To assess transmission between the 2 populations, blood samples were collected from naïve pigs in facility B at designated intervals and tested by PCR. A total of 7 replicates were conducted. During 2 of 7 replicates (1 and 5), PCR-positive ochre-eyed houseflies were recovered in facility B and pigs in this facility became infected with PRRSV. Chi-squared analysis indicated that the presence of PRRSV in an insect sample was significantly (P = 0.0004) associated with infection of facility B pigs. Porcine reproductive and respiratory syndrome virus was not recovered from other reported routes of transmission during the study period, including air, fomites, and personnel. In conclusion, while an insufficient number of replicates were conducted to predict the frequency of the event, houseflies may pose some level of risk for the transport and transmission of PRRSV between pig populations under field conditions.  相似文献   

12.
The current study was performed to determine if porcine reproductive and respiratory syndrome virus (PRRSV) could be transmitted to pigs by feeding muscle tissue obtained from recently infected pigs. Muscle obtained from pigs infected with either a European strain (EU donor pigs) or American strain (US donor pigs) of PRRSV was fed to PRRSV-free receiver pigs. The donor pigs were slaughtered 11 days post-infection (dpi). PRRSV was detected by conventional virus isolation in muscle at 11 dpi from 7 of 12 EU donor pigs and 5 of 12 US donor pigs. In contrast to conventional virus isolation, all muscle samples from infected pigs were positive for viral nucleic acid by PCR, except for muscle from one animal infected with the American strain of PRRSV. Five hundred grams of raw semimembranosus muscle from each of the donor pigs was fed over a 2 days period (250 g per day) to each of two receiver pigs (48 receiver pigs). The receiver pigs were housed separately in five groups. One of the five groups was fed muscle obtained from US donor pigs that was also spiked with the American strain of PRRSV. Sentinel pigs were placed in-contact with the group of receiver pigs fed spiked muscle. All receiver pigs became viraemic by 6 days post-feeding (dpf). There was evidence of horizontal transmission with sentinel pigs, in-contact with receiver pigs, becoming viraemic. The study demonstrates that PRRSV could be infectious through the oral route via the feeding of meat obtained from recently infected pigs.  相似文献   

13.
OBJECTIVE: To determine whether flies can acquire porcine reproductive and respiratory syndrome virus (PRRSV) and disperse the virus throughout a designated area. ANIMALS: 60 four-month-old pigs. PROCEDURE: On day 0, 28 of 60 pigs were inoculated with PRRSV MN 30-100 (index variant). On the same day, 100,000 pupae of ochre-eyed houseflies and 100,000 pupae of red-eyed (wild-type) houseflies were placed in the swine facility for a release-recapture study. Flies were recaptured at 2 locations within the swine facility, 6 locations immediately outside the facility, and 30 locations 0.4, 0.8, 1.3, 1.7, 1.9, and 2.3 km from the facility. Traps were emptied on days 2, 7, 8, 10, and 14. Samples derived from flies were tested by use of a polymerase chain reaction assay, virus DNA was sequenced, and viruses were tested for infectivity by means of a swine bioassay. RESULTS: PRRSV RNA homologous to the index PRRSV was detected in trapped flies collected inside and immediately outside the facility and from 9 of 48 samples collected at 0.4 km, 8 of 24 samples collected at 0.8 km, 5 of 24 samples collected at 1.3 km, and 3 of 84 samples collected at > 1.7 km from the facility. Two samples collected at 0.8 km contained genetically diverse variants of PRRSV. Swine bioassays revealed the virus in flies was infectious. CONCLUSIONS AND CLINICAL RELEVANCE: Flies appeared to become contaminated with PRRSV from infected pigs and transported the virus > or = 1.7 km. Fly-born transmission may explain how PRRSV is seasonally transported between farms.  相似文献   

14.
The purpose of this study was to evaluate the ability of a commercial air-filtration system to reduce aerosol transmission of Porcine reproductive and respiratory syndrome virus (PRRSV). The system consisted of a pre-filter and 2 filters with EU8 and EU13 ratings. In each of 4 trials, 5 PRRSV-infected donor pigs and 1 naive recipient pig (each 25 kg) were housed in opposing chambers connected by a 1.3-m-long duct. The system filtered air entering 1 recipient-pig chamber (filtered facility) from the donor-pig chamber but not a 2nd recipient-pig chamber (nonfiltered facility). The donor pigs had been experimentally infected with PRRSV MN-184, an isolate previously documented to be shed at a high frequency in contagious aerosols. On days 3 to 7 after infection of the donors, the 2 groups were housed in their respective chambers for 6 h and then in separate facilities, where samples were collected for testing by polymerase chain reaction and enzyme-linked immunosorbent assay over 14 d. Aerosol transmission was observed in 6 of the 20 replicates in the nonfiltered facility, whereas all pigs remained PRRSV-negative in the filtered facility; the difference was significant at P < 0.01. Thus, under the conditions of this study, the air-filtration system evaluated appeared to be highly effective at reducing aerosol transmission of PRRSV.  相似文献   

15.
The ability of genetically diverse strains of porcine reproductive and respiratory syndrome virus (PRRSV) to coexist in a 1750-sow farm was assessed through the case study describing a chronically infected farm, and also by an animal experiment involving the use of swine bioassay. The case study employed a program of monitoring sera from suckling, nursery, and finishing pigs for the presence of PRRSV by polymerase chain reaction (PCR) and virus isolation (VI). The swine bioassay tested homogenates, consisting of lymphoid and pulmonary tissues, collected from 60 breeding animals from the same farm. The open reading frame (ORF) 5 portion of selected positive PRRSV detected from sera or tissues were nucleic acid sequenced and their phylogenies compared. The results indicated the presence of 3 genetically diverse groups, designated PRRSV-A, -B, and -C. Sequence heterology ranged from 5.8 to 11% between groups. Sequence homology ranged from 98.7 to 99.8% within groups. Swine bioassay verified the presence of PRRSV-A in 1 of 60 animals, and no evidence of strains B or C were detected. This paper indicates that based on the evaluation of ORF 5, genetically diverse strains of PRRSV appear to coexist, although the frequency and significance of this observation is not understood.  相似文献   

16.
The aim of this study was to develop a model to evaluate the aerosol transmission of porcine reproductive and respiratory disease virus (PRRSV). PRRSV (MN 30-100 strain, total dose 3 x 10(6) virus particles) was aerosolised and transported up to 150 m and a portable air sampler was used to collect air samples at 1, 30, 60, 90, 120 and 150 m (five replicates at each distance) and the air samples were tested by TaqMan PCR and virus isolation. The infectivity of the aerosolised PRRSV was tested by exposing six PRRSV-naive pigs for three hours to aerosolised virus that had been transported 150 m. PRRSV RNA was detected in all five replicate air samples collected at 1, 30, 60 and 90 m, in four of the five collected at 120 m, and in three of the five collected at 150 m. Infectious PRRSV was detected by virus isolation at 1 and 30 m (all five replicates), 60, 90 and 120 m (three of the five) and 150 m (two of the five). There was a 50 per cent reduction in the log concentration of PRRSV RNA every 33 m. Three of the six pigs exposed to PRRSV-positive aerosols became infected, and PRRSV RNA was detected in air samples and on swab samples collected from the interior of the chambers that housed the infected pigs while they were being exposed.  相似文献   

17.
Mechanical transmission of porcine reproductive and respiratory syndrome virus (PRRSV) throughout a coordinated sequence of events that replicated common farm worker behavior during warm weather (10°C to 16°C) was assessed using a field-based model. The model involved fomites (boots and containers), vehicle sanitation, transport, and personnel movement. In a previous study, the model successfully demonstrated mechanical transmission of PRRSV in 8 out of 10 replicates during cold weather. A field strain of PRRSV was inoculated into carriers consisting of soil samples, which were adhered to the undercarriage of a vehicle. The vehicle was driven approximately 50 km to a commercial truck washing facility where the driver's boots contacted the carriers during washing, introducing the virus to the vehicle interior. The vehicle was then driven 50 km to a simulated farm site, and the driver's boots mechanically spread virus into the farm anteroom. Types of containers frequently employed in swine farms contacted drippings from the footwear on the anteroom floor. The truck wash floor, vehicle cab floor mats, boot soles, anteroom floor, and the ventral surface of containers were sampled to track the virus throughout the model. Ten replicates were conducted, along with sham-inoculated controls, and control replicates. In 2 replicates, infectious PRRSV was detected on the anteroom floor and in 1 replicate, infectious PRRSV was detected on the surface of the container by swine bioassay. All sham-inoculated controls and protocol controls were negative. These results indicate that mechanical transmission of PRRSV throughout a coordinated sequence of events in warm weather can occur, but in contrast to data from studies conducted during cold weather, it appears to be a relatively infrequent event.  相似文献   

18.
A series of three experiments, differing primarily in airflow volume, were performed to evaluate the likelihood of airborne transmission of Porcine Reproductive and Respiratory Syndrome Virus (PRRSV) from infected to non-infected pigs. Pigs were housed in two units (unit A and unit B) located 1m apart and connected by pipes. The air pressure and diameter of the pipes, depending on experiments, were strictly controlled to allow desired airflow volumes from unit A to unit B. Either 25 (experiment 1 and experiment 3) or 26 (experiment 2) pigs infected recently with PRRSV, and either 25 (experiment 1 and experiment 3) or 17 (experiment 2) pigs from a PRRSV-free herd, were housed in unit A. Either 50 pigs (experiment 1 and experiment 3) or 43 pigs (experiment 2) from a PRRSV-free herd were housed in unit B. The amount of air transmitted from unit A to unit B, expressed as a percentage of ventilation intake, was approximately 70, 10, and 1% for experiment 1, experiment 2 and experiment 3, respectively. Blood samples were collected from all pigs once per week and analyzed for antibodies against PRRSV. Based on these methods, airborne transmission of PRRSV from infected to non-infected pigs was confirmed in each of the three experiments.  相似文献   

19.
2009年1月—2011年12月,从河南省信阳和驻马店地区62个猪场共收集免疫过猪瘟病毒(CSFV)、伪狂犬病毒(PRV)、猪繁殖与呼吸综合征病毒(PRRSV)和猪圆环病毒2型(PCV2)疫苗的猪血液,利用ELISA方法对样品进行抗体水平的检测。结果显示:该地区猪场猪群的疫苗免疫合格率最高是PRV疫苗(87.06%);其次是CSFV疫苗(76.24%);PRRSV和PCV2的疫苗免疫合格率较低,分别为65.20%和50.78%。4种疫苗免疫抗体合格率在不同规模的猪场有较大的差别,规模猪场的猪群某些疫病的抗体未必比散养猪群高。种猪群的4种疫苗的免疫合格率最高,商品猪中各个生长阶段的免疫后抗体合格率比较后发现,断奶仔猪群PRRSV抗体合格率明显高于哺乳仔猪,育肥猪群合格率要比哺乳仔猪群和断奶仔猪群的抗体合格率低。  相似文献   

20.
为了解德保黑猪主要疫病流行状况和免疫效果,2018—2020年釆集166个德保黑猪饲养场点的300份病死猪样品进行非洲猪瘟(ASF)、猪瘟(CSF)、口蹄疫(FMD)、猪繁殖与呼吸综合征(PRRS)、猪伪狂犬病(PR)、猪圆环病毒病(PCV-2)、猪支原体病(PPLO)、猪传染性胸膜肺炎(PCP)、猪链球菌病(SS)、...  相似文献   

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