The structure, dynamics and movement patterns of the Australian sheep industry

Objective To describe the structure of Australia's sheep industries and the movement of sheep to enable examination of the potential for animal movements to spread disease between farms. Procedure The structure, size, marketing and movement patterns of Australian sheep farms was determined through (i) review of data published by the Australian Bureau of Statistics and Australian Bureau of Agricultural and Resource Economics, (ii) interviews with producers and saleyard managers and (iii) expert opinion. Results Twelve geographic regions are described, based on the type and extent of sheep farming in each region. Five production sectors were identified within the Australian sheep industry, with the proportion of each varying between the geographic regions. Over the past 20 years, the industry has decreased in size and contracted from the northern and central areas of Australia. Movement of sheep onto the majority (79%) of properties was limited to the introduction of less than 50 stud rams annually, although cross‐bred‐ and wether‐based farms introduced up to 2000 sheep annually; 75% of sheep movements occurred over distances less than 200 km, but stud rams moved up to 500 km. An increasing percentage of movements off farms was direct to abattoirs and over 80% of sheep sold through saleyards were purchased by abattoirs. Conclusions The majority of Australian sheep farms operate as self‐replacing enterprises and introduce few stock. In addition, most sheep movements occur over distances of less than 200 km and therefore sheep movements within Australia have only a limited potential to spread disease over larger distances.     

Antimicrobial use in the Australian pig industry: results of a national survey

Objective   To describe how various antimicrobials are used in commercial pig herds in Australia and for what disease conditions.
Procedure   Managers of large pig herds (> 200 sows) across Australia and their veterinarians participated in an internet-based survey in 2006. Questions were asked about herd management, the occurrence of bacterial diseases and the type and frequency of antimicrobial use. An antimicrobial usage index for each herd was derived as a summary of the risk of selection for antimicrobial resistance. Relationships between responses were explored with univariate and multivariate analysis.
Results   Responses were received for 197 herds estimated to represent at least 51% of all large pig herds in Australia. Most piggeries relied on drugs of low importance in human medicine (e.g. tetracyclines, penicillins and sulfonamides). For the two drugs of high importance in human medicine that can be legally prescribed to pigs in Australia, ceftiofur use was reported in 25% of herds and virginiamycin in none. Infections attributed to Lawsonia , Mycoplasma and Escherichia coli motivated the most use of antimicrobials. No useful association was found between management factors and the antimicrobial use index.
Conclusion   Most antimicrobial use in the Australian pig industry is based on drugs of low importance to public health. Enhanced control of E. coli infections without reliance on antimicrobials would further reduce the risk of selecting for antimicrobial resistance relevant to public health. The amount of variation in the usage index between herds suggests that antimicrobial use should be constantly reviewed on a herd by herd basis.     

Epidemiological studies of pig diseases: 1. Use of French protocols for risk factor assessment to predict the health status of Australian herds

Objective To determine in Australian pig herds the accuracy of French protocols for risk factor assessment.
Procedure Data on health indicators and risk factors were collected for three syndromes, 'pre-weaning diarrhoea', 'post-weaning diarrhoea' and 'respiratory problems', using the French protocols. The protocols were used on 118 occasions in 32 Western Australian pig herds during 3 years (1988 to 1991).
Results There was a wide variation in pre-weaning performance, for example growth rate was 107 to 273 g/day (< 200 g/day in 33% of herds). Respiratory lesions at weaning were associated with poor pre-weaning performance. Post-weaning (21 days after weaning) growth rate was 114 to 408 g/day (< 250 g/day in 54% of herds). In the grower herds, 91% of herds had pneumonia, and growth rate was 439 to 625 g/day (< 550 g/day in 54% of herds). Pleurisy as well as pneumonia was associated with reduced growth rate. The risk factor most closely associated with respiratory health status was air volume per pig.
Conclusion Risk factors were most accurate at predicting the health status in post-weaning problems. A weaning weight of at least 7.9 kg and weaning age of 30 days optimised weaner performance. Stocking densities and shed designs providing at least 3 m³ air volume and 0.6 m² floor space per pig throughout the growing phase should be considered for an improved respiratory health status. Australian pig sheds often do not provide a satisfactory environment for optimum health. The technique of risk factor assessment as an aid to the maintenance of health in pig herds is applicable in Australia, but further research is necessary to determine the most important Australian risk factors.     

Assessment of the risks of communicable disease transmission through the movement of poultry exhibited at agricultural shows in New South Wales

Objective To assess biosecurity practices in the fancy poultry show sector that would influence the establishment and spread of exotic diseases in poultry in New South Wales. Design A cross-sectional survey of 105 fancy poultry exhibitors at seven agricultural shows. Procedure Exhibitors were interviewed about biosecurity practices on their farms and their knowledge of exotic diseases. Poultry stewards at 18 shows were interviewed about biosecurity practices at their shows. Results Although many exhibitors travelled only short distances to attend shows, some exhibitors attended up to 30 shows per year and travelled interstate to exhibit poultry. A network diagram revealed extensive connections and interactions of poultry throughout the eastern half of NSW. Five of 18 shows included cash sales without any record of purchasers; 46% of exhibitors reintroduced exhibited birds back into their flocks without a quarantine period; and 16% failed to wash cages used to transport the birds. There was a general awareness that exhibition of birds posed a risk to flock health, but knowledge of avian influenza and practices that could be adopted to minimise the risk of disease introduction was limited. Conclusions The factors that could assist the establishment and spread of exotic diseases in poultry in NSW include the mixing of birds at shows, inadequate recording of exhibitor details at shows, inadequate biosecurity practices when reintroducing exhibited poultry back into flocks, cash sales associated with shows that did not include the collection of purchaser details, and inadequate identification of birds.     

Epidemiological studies of pig diseases: 2. Post-weaning diarrhoea and performance in Western Australian pigs

Objective To determine in Australian pig herds the accuracy of French protocols for risk factor assessment of post-weaning diarrhoea and illthrift.
Procedure French protocols for the collection of data on health indicators and risk factors for post-weaning diarrhoea were conducted on 54 batches of weaner pigs from 28 Western Australian pig herds during three years.
Results Large variations in post-weaning performance were found. About one-third of the batches were growing at <200 g/day during the 3 weeks after weaning, and 54% had growth rates of <250 g/day. Weaning age and weight of at least 30 days and 7.9 kg, respectively, optimised weaner performance. Other risk factors associated with little post-weaning diarrhoea and good weaner performance were high creep feed intakes, relatively little diarrhoea as suckers, and, contrary to expectations, large temperature fluctuations.
Conclusion Overall, the 'predictability' of post-weaning problems as assessed by measurement of risk status, was good. However, the model was less accurate at predicting the performance of a single batch of pigs.     

Adoption of biosecurity practices in the Australian poultry industries

OBJECTIVE: To determine the level of adoption within the Australian poultry industries of a range of standard biosecurity practices. DESIGN: A questionnaire survey of owners and managers of 1753 commercial poultry farms. Procedure Information was collected by telephone or in person from the owners and managers of poultry farms. Data were entered onto an Excel spreadsheet and analysed using the statistical tools within Excel. RESULTS: The response rates to the questionnaire for the chicken meat, egg, duck and turkey sectors were 94%, 37%, 92% and 96% respectively. Within the chicken meat sector, the adoption rate exceeded 98% for 11 practices with only the rates for appropriate disposal of spent litter/manure (94%) and development of farm level biosecurity plans (88%) falling below this level. Adoption rates for all practices had increased or remained at 100% since the last survey conducted in 2001. Integrated companies in the turkey and duck sector also reported high levels of adoption for most biosecurity practices although rates for the use of fresh litter, cleaning of sheds between batches of birds and maintenance of single age flocks were lower than in the chicken meat sector. Adoption rates for biosecurity practices on independently owned farms in the turkey and duck sectors were lower than for farms operated by integrated companies. CONCLUSIONS: Farms in the chicken meat, turkey and duck sectors of the Australian poultry industries have a high level of adoption of biosecurity practices with only a small proportion of farms needing to further enhance their biosecurity.     

Evaluation of the implementation of new traceability and food safety requirements in the pig industry in eastern Australia

Objectives   To evaluate the implementation and barriers to adoption, among pig producers, of a newly introduced traceability and food safety system in Australia.
Procedure   Implementation of the PigPass national vendor declaration (NVD) linked to an on-farm quality assurance (QA) program was evaluated in May and December 2007 at saleyards and abattoirs in New South Wales, Victoria and Queensland. Four focus group discussions with saleyard producers were held between April and July 2007.
Results   Implementation of the PigPass system in terms of accurate completion of the form and QA accreditation was higher at the export abattoir than at the regional saleyard at the first audit (P < 0.01). Implementation increased at the second audit at the abattoirs, but little change with time was observed at saleyards. Approximately half of the producers at saleyards used photocopied PigPass forms, made at least one error (>64%), and many vendors did not appear to be QA-accredited. During focus groups, producers expressed the view that PigPass implementation improved animal and product traceability. They identified the associated costs and a perceived lack of support by information providers as obstacles for adoption.
Conclusion   Improvement in the implementation of PigPass among producers marketing pigs at export abattoirs was observed during the 8-month period of the study. There is a need for a more uniform message to producers from government agencies on the importance of the PigPass NVD and QA and extension and education targeted toward producers supplying pigs to saleyards and domestic abattoirs to ensure compliance with the traceability requirements.     

Knowledge and attitudes of Australian livestock producers concerning biosecurity practices

Biosecurity risks are a major threat to the profitability of the industry as well as impacting human and animal health. Livestock producers play a crucial role in biosecurity as the first to notice changes in the health or productivity of their stock and are generally responsible for implementing protective measures. However, uptake of biosecurity measures by producers is variable. We critically appraised the current literature regarding biosecurity practices in Australian livestock industries and highlight aspects that are well understood as well as those where further research or information is needed. Findings from 12 cross-sectional studies suggest that Australian producers' knowledge of biosecurity methods and importance might have a positive influence on their willingness to implement or incorporate biosecurity practices. There is moderate evidence supportive of biosecurity being well understood by livestock producers across Australia. Barriers to producers using biosecurity practices included lack of information or communication from agricultural, veterinary or government organisations. It was found that larger stock numbers were positively correlated with biosecurity implementation and that producers used veterinarians, government and industry agencies as resources for trusted information.     

Serological responses to two serovar‐independent ELISA antigens of Actinobacillus pleuropneumoniae in Australian commercial pig herds

Objective To compare serological responses in pig herds classified as low or high risk for disease caused by Actinobacillus pleuropneumoniae, using two ELISA tests based on serovar‐independent antigens. Procedure Cross‐sectional sampling was undertaken in 13 commercial herds, the clinical and slaughter histories of which indicated either freedom from (n = 5) or prior confirmed cases of A. pleuropneumoniae (n = 8). In nine herds, approximately 40 pigs each were sampled at 4, 8, 12, 16 and 20 weeks. Three of the remaining four herds were sampled between 6 and 30 weeks of age, and the last was sampled only prior to slaughter, at approximately 24 weeks. Sera were tested in ELISA based on two antigens common among A. pleuropneumoniae serovars: a 39‐kDa outer membrane protein and a recombinant ApxIVA‐N terminus protein. Results Sampling of 1 and 5 to 6‐month‐old pigs provided the most useful information on herd status. The 39‐kDa ELISA was sensitive in detecting infected herds, but had evidence of cross‐reactivity with high seroreactivity rates in older pigs in some low‐risk herds. The ApxIVA‐N ELISA was less seroreactive in high‐risk herds and had higher specificity in low‐risk herds. Conclusion ELISA based on the 39‐kDa subunit are of limited use, because of possible cross‐reactivity, but a high negative predictive value may be useful for risk assessment in suspect herds. Maternal antibody to ApxIVA‐N may be of value in detecting high‐risk herds, but 5% of 4‐week‐old pigs in low‐risk herds were also seropositive in this assay.     

Incidence of presenting complaints and diagnoses in insured Australian dogs

Knowledge of the most common presenting complaints and diagnoses in companion animals is valuable in preparing veterinary students and veterinarians to manage the most frequently observed conditions in clinical practice. Pet insurance databases provide access to large sample populations and have been previously used to describe disease incidence in companion animals. The aim of this study was to determine the incidence of presenting complaints and diagnoses in insured Australian dogs through the use of a pet insurance database. Analysis of a de-identified dataset containing pet insurance claims associated with presenting complaints and diagnoses from 488,472 insured Australian dogs insured in the years 2016 and 2017, was performed. Annual incidence rates of presenting complaints and diagnoses were calculated and expressed as, number of events per 1,000 dog years at risk. The presenting complaints with the highest incidence were vomiting (14.21 events per 1,000 dog years at risk in 2016, 15.80 events per 1,000 dog years at risk in 2017) and pruritus (8.79 events per 1,000 dog years at risk in 2016, 10.30 events per 1,000 dog years at risk in 2017). Presenting complaints affecting the gastrointestinal system were the most common (19.20 events per 1,000 dog years at risk in 2016, 20.77 events per 1,000 dog years at risk in 2017). The diagnoses with the highest incidence were otitis externa (34.12 events per 1,000 dog years at risk in 2016, 34.82 events per 1,000 dog years at risk in 2017) and dermatitis (28.05 events per 1,000 dog years at risk in 2016, 29.99 events per 1,000 dog years at risk in 2017). Diagnoses affecting the integument were the most common (216.56 events per 1,000 dog years at risk in 2016, 219.06 events per 1,000 dog years at risk in 2017). The results from this study can aid in the design of relevant veterinary curricula and may be helpful in prioritising research on common clinical conditions.     

一起境外输入性牛结节性皮肤病疫情

2020年11月,山东滨州市、东营市引进牛皮肤出现自限性皮肤结节、损伤以及结痂等症状,疑似发生牛结节性皮肤病（lumpy skin disease,LSD）。为确诊两地疫情及了解病原的遗传演化关系,利用荧光定量PCR方法进行诊断,以PCR方法扩增GCPR基因并进行核苷酸比对分析和遗传演化分析。检测结果显示,采集的样品中检测到牛结节性皮肤病病毒（lumpy skin disease virus,LSDV）,两地疫情确诊为LSD疫情。GCPR基因核苷酸比对结果显示,China/SDBinzhou/2020、China/SDDongying/2020 GCPR基因存在12个核苷酸的插入,与疫苗毒株Neethling vaccine LW 1959株、Neethling-LSD vaccine-OBP株以及俄罗斯发现的疫苗样毒株Saratov株在GCPR基因的核苷酸插入序列相同,具备疫苗样毒株的特征。系统发育分析结果表明,China/SDBinzhou/2020、China/SDDongying/2020 GCPR基因与我国新疆发现的LSDV毒株GCPR基因处同一小分支中,亲缘关系较近。同时,我国LSDV毒株与Neethling vaccine LW 1959株、Neethling-LSD vaccine-OBP株以及Saratov株等共处于一大分支中。综上,确诊滨州市、东营市两地疫情为LSD疫情,这是山东省首次确诊输入性LSD疫情。     

Antibiotic resistant Escherichia coli in southeastern Australian pig herds and implications for surveillance

To investigate public health implications of antibiotics to control post‐weaning scours, we surveyed 22 commercial pig herds in southeastern Australia. Fifty faecal samples per herd were collected from pre‐ and post‐weaned piglets. Presumptive Escherichia coli isolates were confirmed by MALDI‐TOF MS. Isolates (n = 325) were screened for susceptibility to 19 veterinary antibiotics using MIC broth microdilution. All 325 E. coli isolates underwent further testing against 27 antibiotics used in human medicine and were screened for ETEC adhesin and enterotoxin genes (F4 (K88), F5 (K99), F6 (987P), F18, F41, STa, STb, Stx2e and LT) by multiplex PCR. Isolates identified as phenotypically resistant to third‐generation cephalosporin (3GC) and aminoglycoside antibiotics were screened by multiplex PCR/reverse line blot to detect common β‐lactam and aminoglycosides resistance genes, confirmed by sequencing. Twenty (6.1%) of the E. coli isolates were resistant to 3GC antibiotics and 24 (7.4%) to the aminoglycoside antibiotic gentamicin. Genetic analysis revealed six different extended spectrum β‐lactamase (ESBL) genes (blaCTX‐M‐1, ‐14, ‐15, ‐27, blaSHV‐12 and blaCMY‐2‐like genes), four of which have not been previously reported in Australian pigs. Critically, the prevalence of 3GC resistance was higher in non‐pathogenic (non‐ETEC) isolates and those from clinically normal (non‐diarrhoeal) samples. This highlights the importance of non‐ETECE. coli as reservoirs of antimicrobial resistance genes in piglet pens. Antimicrobial resistance surveillance in pig production focused on diagnostic specimens from clinically‐affected animals might be potentially misleading. We recommend that surveillance for emerging antimicrobial resistance such as to 3GC antibiotics should include clinically healthy pigs.     

推进生猪“四化”建设提高养猪效益——沪、浙、粤生猪产业化考察启示

为全面贯彻落实科学发展观,推进生猪产业化建设,降低畜禽养殖对环境的污染,促进农民增收,实现生猪产业又好又快发展,我们先后赴上海、浙江和广东学习考察。通过对3个省市的实地考察与交流,收获很大,开阔了视野,转变了观念,丰富了知识,看到了差距,同进也坚定了信心,激发了干劲。