人类在禽病流行中所扮演的角色

彻底阐明疾病从人向家禽传播的途径并不是一件困难的事,但要防止家禽疾病暴发还需要走很长的路。     

Evaluation of methods for the euthanasia of cattle in a foreign animal disease outbreak.

In anticipation of the need to euthanize large numbers of cattle in the event of a foreign animal disease outbreak, two models of captive bolt gun and various firearms and ammunition loads were tested in order to assess their suitability. In the first phase of the project, two models of captive bolt stunner were used in an abattoir, and assessed for effectiveness. In the second phase, several firearms and ammunition were used on isolated bovine heads and assessed for effectiveness. Little difference was found between the two captive bolt stunners. Of the firearms and ammunition evaluated, the Ruger Mini-14 and the Core-Shot round, a prefragmented projectile, were determined to be most suitable. In situations where large herds of livestock are to be depopulated, and where the restraint required for the use of captive bolt stunners is not practical, there are commercially available firearms and ammunition that are suitable for this purpose.     

Pasteurella multocida as the cause of disease outbreaks in commercial poultry flocks

Six cases of fowl cholera in growing turkeys and 3 in adult breeder chickens of the broiler type as well as one case each of a Pasteurella (P.) multocida-associated disease in ducklings and goslings were described in consideration of own laboratory findings and available informations of the case history. Furthermore a report is given on a treatment strategy successfully used in turkeys with highly acute fowl cholera. All the P. multocida strains isolated culturally could be assigned to the subspecies multocida. In one case Bordetella avium, Salmonella (S.) arizonae and S. hadar were additionally cultured form part of turkeys submitted. P. multocida and Moraxella (Pasteurella) anatipestifer could be determined as the causative agents of the disease of ducklings and goslings. P. multocida strains from turkeys were identified serologically as serovars A:3.4 (3x), F:3.4 (2x) and A:3 (1x); those from the breeder chickens as A:3 (3x); and one each from ducklings and goslings as F:3.4 and -:3. (uncapsulated). No death occurred in turkeys with clinical signs of a highly acute fowl cholera if the treatment of the affected birds was started with an intravenous injection of sulfadimethoxine and continued with a combination of sulfachlorpyridazine (SCP) and trimethoprim (TMP) given in the drinking water for 5 days. However relapse occurred 2-3 days after withdrawal of the drug, although the therapy was clinically highly effective. The recurrence of the disease could be prevented reliably if the turkeys were vaccinated with an effective oil-based bacterin and subsequently treated with the SCP-TMP combination given in drinking water over a 12 day period.     

Review of gaseous methods of killing poultry on-farm for disease control purposes

Poultry may need to be culled in the event of an outbreak of disease. Gassing has advantages over mechanical and electrical methods or overdoses of anaesthetics because large numbers can be killed simultaneously and little or no handling of the birds is required. However, gaseous killing methods may have welfare implications for the birds, which may find various gases more or less aversive, may undergo respiratory distress and/or experience convulsions, and may remain conscious for a considerable time before they die. In addition, the gases used may present health and safety risks to human operators, and be difficult to supply and deliver.     

节约成本的禽舍建造技术

未来家禽业的发展将面临许多问题。但有一件事是肯定的,那就是多数专家认为,随着丙烷燃气与电力使用成本的不断上升,禽舍的设计与建造将不得不比过去更加关注运营成本,特别是加热与散热成本。     

Epidemiology of recent outbreaks of infectious laryngotracheitis in poultry in Australia

Objective Over the past 3 years, numerous outbreaks of infectious laryngotracheitis (ILT) have occurred in poultry in Australia. The objectives of this study were to identify the viral strains involved in the recent outbreaks and to determine possible epidemiological links between these outbreaks. Procedure A combination of polymerase chain reaction (PCR) and restriction fragment length polymorphism (RFLP) analyses of several genes of the ILT virus was used to identify genetic differences in field/vaccine ILT virus isolates. In a previous study, these procedures had demonstrated five classes (1–5) in Australia. Results Analysis of 92 field ILT viruses demonstrated four new classes: 6, 7, 8 and 9. Class 6 was responsible for four outbreaks in one Victorian broiler company and demonstrated to be distinct from other Australian strains of ILT. Class 7 was the Nobilis ILT vaccine (Intervet Pty Ltd). Class 8 was responsible for the majority of the outbreaks in New South Wales and was phylogenetically close to class 7. On one occasion, classes 7 and 8 were identified in an outbreak on a Victorian farm that had used the Nobilis ILT vaccine. Class 9, also phylogenetically close to classes 7 and 8, was found only in New South Wales. The previously identified class 2 was also found to be responsible for a large number of outbreaks, mainly in Victoria. Conclusion The results demonstrate that, epidemiologically, most outbreaks of ILT in New South Wales are unrelated to those in Victoria and suggest a link between classes 8 and 9 and the Nobilis ILT vaccine (class 7).     

家禽的抗病育种研究

禽病一直是养禽业的难题,提高家禽的抗病性与健康水平已成为世界养禽业普遍关注的问题。随着分子生物学技术的发展,采用遗传学方法从遗传本质上提高家禽的抗病能力,增强免疫功能的抗病育种则愈发显得重要。本文就抗病育种的遗传基础、抗病育种的方法及其在家禽生产中的成功运用作了简单介绍,最后对抗病育种的发展前景作了展望。     

Comparison of methods for the detection ofSalmonella in poultry

The aim of this study was to compare 2 testing methods forSalmonella in poultry. One-day-old specific-pathogen-free chicks were infected via crop installation with aSalmonella test strain (Salmonella Enterititis phage type 4; Bundesintitut für gesundheitlichen Verbraucherschutz und Veterinärmedizin-No. 01–00554; nalidixic acid resistant). Samples were collected at 7 sample occasions to redetect the agent from the animals and the environment. Using conventional techniques and PCR, the test strain was successively detected in the animals as well as in the environment of the flocks. In comparison, PCR was more effective. First positive findings were obtained from cloacal swabs at the third sampling occasion. Most frequentlySalmonella was obtained from ceca and from spleen samples, indicating that these 2 organs are most suitable forSalmonella testing. Cloacal swabs were positive earlier; however, ceca and spleen samples were positive more consistently. Conventional methods as well as PCR were suitable for detection ofSalmonella.