科技部副部长程津培视察西南农业大学蚕桑学重点实验室

国家科技部程津培副部长一行于近日来到重庆市视察、调研。6月29日下午,程津培副部长在重庆市科委主任周旭的陪同下莅临西南农业大学。学校在生物工程大楼蚕桑学重点实验室报告厅召开了工作汇报会。中国工程院院士向仲怀与校领导华鹏、周泽扬、张家骅及其有关部门负责人参加了会议。     

A Swiss case-control study to assess Neospora caninum-associated bovine abortions by PCR, histopathology and serology.

Neospora caninum is one of the most frequent infectious organisms causing abortion in cattle worldwide. The present case-control study was designed to assess the importance of bovine neosporosis for causing abortion in Swiss cattle and to identify selected risk factors. Infection was primarily diagnosed by a N. caninum-specific PCR and serology, complemented with histopathology and immunohistochemistry. A total of 113 case and 113 corresponding control-farms were studied for 1.5 year. During this time period, 242 abortions were reported and referred for bacteriological, virological, parasitological and pathohistological examinations. N. caninum was detected by PCR in the brains of 21% of all aborted fetuses. Microscopic lesions indicative for cerebral protozoa infection were detected in 84% of PCR-positive fetal brains. Bovine viral diarrhea virus (BVDV) was demonstrated in 7% of the cases, and bacterial infections were detected in 4% of the abortions. One or more N. caninum-abortions occurred in 20% of the herds (41 case-farms and 3 control-farms). Serological examination of aborting mother cows revealed a significantly higher percentage of N. caninum-seropositive animals (44%) in comparison to the prevalence in a randomly selected population (12%). However, in eight cases (4% of all investigated abortions) seronegative cows aborted N. caninum PCR-positive fetuses, and in 50 cases the fetus remained negative although the respective mother cow was N. caninum-seropositive. Repetitive serological investigations (at a 3-12 months interval) of 3551 cows from case- and control-farms showed a decrease of the overall N. caninum-seroprevalence from 17 to 12%. Ninety out of 3008 seronegative animals were converted to N. caninum-seropositivity. Conversely, 212 out of 543 initially seropositive animals became seronegative for their second serum sample. The obtained data underlined the importance of N. caninum as a causative agent for abortion in Swiss cattle. Furthermore, PCR was confirmed to be a valuable diagnostic tool for the primary diagnosis of N. caninum in aborted fetuses. On the other hand, the value of serology appears to be hampered by the temporal instability of N. caninum antibody concentrations in adult cattle, including especially seronegativity of some individual animals. Thus, seronegativity in a mother cow or heifer does not exclude N. caninum-associated abortions.     

Trends and seasonal variations in the occurrence of Salmonella in pigs, pork and humans in Denmark, 1995-2000

A mandatory programme monitoring the occurrence of Salmonella in pork at slaughterhouses and a serological monitoring of slaughter-pig herds has been implemented in Denmark since 1993 and 1995, respectively. All results are stored in a central database. From this, aggregated weekly results of serological and bacteriological samples collected in the period between January 1995 and July 2000 were extracted. In addition, the reported weekly incidence of human infections with S. Typhimurium covering the same time period was obtained. The times series were analysed for trends and cyclic variations by seasonal decomposition. The association between the incidence in humans and the prevalence of Salmonella in pigs and pork, and prevailing weather conditions, were analysed by using a general linear (glm) and a general additive model (gam). Explanatory variables were lagged to account for time elapsed between sampling, consumption, incubation period and case registration. The results of the seasonal decomposition showed an overall declining trend in all three time series. All time series exhibited a double peaked annual cycle. The seasonal variation of the prevalence in pork and the human incidence had a very similar course. The variables that were both biologically meaningful and statistically significant in both regression models were the prevalence in pork sampled 4 to 5 weeks before case registration, the seroprevalence, measured as the average prevalence of week 15 to 35 before case registration, and the air temperature lagged at 2 and 3 weeks. Limitations on inferences from overall surveillance data are discussed.     

科技部程津培副部长视察西南农业大学蚕桑学重点实验室时的讲话

西南农业大学是在农学上很强的单位。做了很多工作,培养了许多杰出人才,如袁隆平院士、向仲怀院士等。在水稻品种、玉米品种、动物研究、生物工程特别是基因研究等方面做了很多工作。在蚕桑研究方面有很强的实力,有60余年的积累,在世界上率先完成了家蚕基因组框架图,科研方向、选择的目标很对,提出“构建21世纪丝绸之路”的目标明确。通过国际合作与竞争,把世界上蚕桑科研方面的力量凝聚到我们中国。蚕丝产量我国最大,但产业是否最大?尤其是包括扩展到生物制药、害虫生物防治的大产业。     

农业部现行规章清理结果

为全面推进农业依法行政工作,维护农业法制统一,根据《国务院办公厅关于开展行政法规规章清理工作的通知》要求,农业部对建国以来发布的规章进行了全面清理,现选取部分与畜牧业相关的进行刊登。     

Designation of aerotolerant Campylobacter-like organisms from porcine and bovine abortions to the genus Campylobacter

Unusual helically-curved bacteria isolated from porcine and bovine abortions measured 1.8 microns long and 0.4 microns wide, failed to produce poly beta-hydroxybutyric acid granules and had DNA base compositions within the span 29--34 moles per cent. From this evidence, it was concluded that these organisms are members of the genus Campylobacter.     

The relationship between the occurrence of undifferentiated bovine respiratory disease and titer changes to bovine coronavirus and bovine viral diarrhea virus in 3 Ontario feedlots.

Serological evidence of previous viral exposure (titer at arrival) and current viral exposure (titer increase) during a 28-day study period, was used to determine if bovine coronavirus (BCV) or bovine viral diarrhea virus (BVDV) was associated with the occurrence of undifferentiated bovine respiratory disease (UBRD) in feedlot calves. Neutralizing antibody titers to BCV and BVDV were determined for 852 animals from 3 Ontario feedlots. Calves at 2 of the 3 feedlots (n = 753) received a modified live 4-way viral vaccine containing BVDV. On arrival at the feedlots, 90% of animals were seropositive for BCV, while 39% of animals were seropositive for BVDV. This evidence of previous exposure to both viruses was associated with reduced subsequent UBRD risk. Evidence of exposure to BCV during the study period was common, as 50% of animals showed a 16-fold or greater titer increase; however, treatment for UBRD was not associated with titer change. Although the majority of animals were vaccinated for BVDV at arrival, within a feedlot, animals treated for UBRD had larger titer increases to BVDV than non-treated animals. Based on our findings we infer that BCV was not causally related to UBRD occurrence, however consistent with other literature, BVDV may be causally related to UBRD occurrence.     

Diagnostic studies of the fetus, placenta and maternal blood from 265 bovine abortions

During 1981, the fetus, placenta and maternal serum were received from each of 265 bovine abortions. These specimens were examined using histopathological, histochemical, bacteriological, mycological, endocrinological, immunological, serological and virological techniques. The cause of abortion was identified in 98 (37%) cases. Of these diagnosed abortions 27 (28%) were due to infection with fungi, 17 (17%) to Salmonella spp, 11 (11%) to Campylobacter fetus and 10 (10%) to Corynebacterium pyogenes infection. Of the remaining 33 (34%) diagnosed abortions 8 were due to Leptospira sp, 5 due to protozoan (probably Sarcocystis) encephalitis and 20 due to miscellaneous bacterial infections (including Brucella abortus) and fetal deformities. Bovine virus diarrhoea virus was isolated in 5 (2%) abortions, however the significance of the isolations was not known. Infectious bovine rhinotracheitis virus and chlamydia were not identified as causal agents in any abortion. In 18 (7%) abortions no definite etiologic agent was identified despite pathological findings suggestive of infection. Fetal heart blood serology and immunoglobulin values were not reliable indicators of infectious abortion. Of the remaining 149 (56%) abortions, 17% had high maternal serum cortisol levels and twin fetuses occurred in 9%.     

Etiologic agents detected in a 10-year study of bovine abortions and stillbirths.

During a 10-year period, specimens from 8,995 bovine abortions were submitted to the South Dakota Animal Disease Research and Diagnostic Laboratory; 8,962 of these specimens were suitable for examination. A supportable diagnosis was made in 2,942 (32.82%) of the abortions examined. An infectious cause was determined for 2,723 (30.38%) and a noninfectious cause for 219 (2.44%). Bacteria caused 1,299 (14.49%), viruses caused 948 (10.57%), and fungi caused 476 (5.31%). The infectious bovine rhinotracheitis virus was associated with 485 (5.41%) and the bovine viral diarrhea virus with 407 (4.54%). The most common noninfectious causes of abortion or stillbirth were anomalous development, 112 (1.25%); dystocia, 56 (0.62%); and twinning, 37 (0.41%). The cause of 6,020 (67.17%) abortions was not determined. Lesions, many suggesting the presence of infection, were present in 1,554 (17.34%) fetuses or placentas in which no infectious agent could be demonstrated.     

Trends in hip dysplasia control: analysis of radiographs submitted to the Orthopedic Foundation for Animals, 1974 to 1984

From 1974 through 1984, the Orthopedic Foundation for Animals evaluated 143,218 radiographic submissions representing 151 breeds of dogs. All breeds from which there were 35 or more evaluations had some frequency of dysplasia. Seventy breeds, each with over 100 submissions, were tabulated and ranked according to frequency of hip dysplasia. Frequency of dysplasia varied from 0.6% in the Borzoi to 46.9% in the Saint Bernard. These data were compared with data obtained earlier (1966 to 1973) on evaluations in 38 breeds for changes in frequency. There was significant (P less than 0.05) reduction in frequency of dysplasia in 27 breeds, a significant (P less than 0.05) increase in frequency in only 1 breed (German Shorthaired Pointer), and no significant change in frequency in 10 breeds. The median significant decrease was 22.4%, and the range was from 3.1% in the Chesapeake Bay Retriever to 48.7% in the Keeshond. The reduction in frequency of hip dysplasia demonstrated the value of a control program. There were 5 breeds with a significant (P less than 0.05) decrease in frequency of dysplasia that had over 5,000 evaluations from 1974 to 1984. The decreases in frequency were independent of changes in American Kennel Club registrations for these breeds (a dramatic decline in registrations for the German Shepherd Dog and Old English Sheepdog, and a dramatic increase for the Rottweiler, Golden Retriever, and Labrador Retriever). Frequency regressed linearly in the German Shepherd Dog and Old English Sheepdog, but regressed nonlinearly in the other 3 breeds. The percentage reduction in frequency from the base frequency (1966 to 1973) for these breeds was 17.5% for the German Shepherd Dog, 23.1% for the Old English Sheepdog, 9.1% for the Rottweiler, 10.1% for the Golden Retriever, and 6.8% for the Labrador Retriever.     

Practical experiences with the new guidelines "Animal Welfare Aspects for the Organization of Pet Markets"of the German Federal Ministry of Nutrition, Agriculture and Consumer Affairs

Though being controversially discussed in the fore field the new guidelines "Animal Welfare Aspects for the Organization of Pet Markets" of the German Federal Ministry of Nutrition, Agriculture and Consumer Affairs create a standard supported by the main associations of both animal welfare activists and keepers of animals concerned by this subject. This standard was created as a means of achieving high animal welfare standards at these markets all over Germany. First practical experience with the guidelines show that their strict application can greatly improve conditions for the animals. It remains a challenge for the veterinary authorities however to develop inspection concepts for each market jointly with the organizer. Inspections at each event followed by appropriate executive measures further help to ensure conditions in accordance with German Animal Welfare legislation. Besides the opportunity of making conditions with the obligatory licence of pet merchants should be taken.     

A retrospective study of sporadic bovine abortions, stillbirths, and neonatal abnormalities in Atlantic Canada, from 1990 to 2001

In a retrospective study on 265 cases of sporadic bovine abortions, stillbirths, and neonatal deaths in Atlantic Canada (1990 to 2001), an etiological diagnosis was made in 117 cases (44.2%). The cases were divided into 2 groups: 234 abortions, and 31 stillbirths and neonatal deaths. Identified causes of abortion were bacteria (24.4%), fungi (6.8%), viruses (6.0%), protozoa (Neospora spp.) (2.1%), congenital anomalies (0.4%), and miscellaneous conditions (1.3%). In addition, placentitis without demonstrable infectious agents was observed in 17 (7.3%). Of the 31 cases of stillbirth and neonatal death, identified causes were dystocia (22.5%), congenital anomalies (22.5%), meconium aspiration syndrome (16.1%), and miscellaneous conditions (6.5%). No etiological diagnosis was made in 59% of abortions and 32.4% of stillbirths and neonatal deaths. The 3 most common identifiable causes of abortion in this study were bacterial, fungal, and viral infections.