A 300‐sow farrow‐to‐finish herd in New South Wales was infected with influenza pandemic (H1N1) 2009 (H1N1/09) virus in July 2009 and became the first recorded case of influenza in pigs in Australia. ...The outbreak resulted from human‐to‐pig transmission. Clinical signs in affected pigs were mild compared with overseas reports of ‘classical’ swine influenza virus and included coughing and decreased appetite in a small proportion of non‐lactating breeding stock, weaners, growers and finishers. A diagnosis of H1N1/09 influenza virus infection was confirmed using a combination of serology (haemagglutination inhibition, blocking enzyme‐linked immunosorbent assay) and real‐time reverse transcription polymerase chain reaction. Attempts at virus isolation were unsuccessful. Results of a longitudinal study of pigs on this farm suggested that the virus continued to circulate for 9 weeks after the onset of infection, but was not present 6 months later. This report highlights the difficulties in preventing transmission of H1N1/09 influenza virus from infected humans to pigs during a human pandemic.
Case report
This report describes an investigation into the cause of abortions on a commercial pig farm in Victoria in October 2015 in which six sows aborted over a 2‐month period. Four of the ...abortions occurred in the 3 weeks prior to the sows’ anticipated farrowing dates and the other two occurred in the second trimester of pregnancy. An analysis of farm data showed that the abortion rate in the previous 12 months (2014–15) was more than twice that of the previous 2 years (1.2% vs 0.5%). Parity appeared not to be a risk factor for abortions. There were no other indicators of reproductive failure on the farm and there were no obvious clinical signs of disease in affected sows. Placenta and aborted fetuses for postmortem analysis were collected while one of the sows was aborting. The only gross abnormality detected in piglets was reddening over the skin. On gross examination the surfaces of the placentas appeared diffusely thickened and ‘furry’. Histological examination of fixed placenta from one of two piglets showed a severe, acute, multifocal, necrosuppurative placentitis. Gram staining of a histological section of the placenta revealed abundant Gram‐negative short bacilli, consistent with Pasteurella–Actinobacillus spp. A sample of stomach contents from one piglet yielded a profuse predominant growth of bacteria described as Pseudomonas‐like. This organism was subsequently identified using 16sRNA sequencing to have 98% homology with Actinobacillus rossii.
Conclusion
This is the first reported case of A. rossii isolated from an aborted pig’s stomach in 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.
OBJECTIVES: To gather information on producers' perceptions and management strategies towards the detection, alleviation of pain and management of sick, injured and heat‐stressed pigs. METHODS: A ...total of 16 Victorian pig farmers completed a face‐to‐face questionnaire consisting of 9 open and 26 closed questions regarding their detection and management of sick, injured and heat‐stressed pigs and their perceptions of pigs' tolerance to pain. RESULTS: We identified 15 behavioural and physiological indicators of pain and heat stress. Treatment records were kept more often for weaned progeny and lactating sows than for piglets and mated sows. Most producers felt that pigs suffered little pain from routine husbandry procedures and that pain relief was not warranted in those situations. Castration at 10 days of age was the only procedure considered by producers to be very painful. There were inconsistencies in approaches to treating pigs in three case studies of animals with sickness or injury of varying severity. Meloxicam was stated as the most common anti‐inflammatory drug used on‐farm. A small proportion of farmers incorrectly identified antibiotics as anti‐inflammatory drugs. All producers had at least one cooling system in place for preventing heat stress in pigs. CONCLUSIONS: The farmers in this survey group generally relied on behavioural changes in pigs to signal pain and heat stress. Although producers kept treatment records and used hospital pens for compromised pigs, our results suggest that the monitoring of pigs' recovery could be improved. Producers generally have a good understanding of the use of anti‐inflammatory drugs to aid recovery of pigs.
OBJECTIVE: To investigate risk factors and potential infectious aetiologies of an increased mummification rate (>2%) identified over time on a 1200‐sow farrow‐to‐finish farm in Australia. METHODS: ...Association of potential non‐infectious risk factors and the mummification rate was investigated using 15 years of breeding herd data (40,940 litters) and logistic regression analysis. Samples from a limited number of mummified fetuses were taken to identify potential infectious aetiologies (porcine parvovirus, Leptospira pomona, porcine circovirus type 2, Bungowannah virus and enterovirus). RESULTS: Logistic regression analysis suggested that the mummification rate was significantly associated with sow breed and parity, year and total born and stillborn piglets per litter. The mummification rate was lower (P < 0.001) in Landrace (3.4%) and Large White (2.6%) sows than in Duroc sows (4.9%). Gilts (2.9%) had a lower (P < 0.001) mummification rate than older sows. The mummification rate increased with total born litter size and decreased with the number of stillborn piglets (P < 0.001). A clustering effect within individual sows was identified, indicating that some sows with mummified fetuses in a litter were more likely to have repeated mummifications in subsequent litters. No infectious agents were identified in the samples taken. CONCLUSION: Results from this study suggest that the increased mummification rate identified over time on this farm is likely to be a non‐infectious multifactorial problem predisposing the occurrence of mummification. Further research is required to better understand the pathophysiology of mummification and the role that different non‐infectious factors play in the occurrence of mummified fetuses.
Impaired reproductive performance exhibited by the domestic sow during the late summer and early autumn months is referred to as seasonal infertility. This study was carried out to determine whether ...there are changes in ovarian morphology and follicular steroidogenesis associated with season, which may be associated with seasonal infertility. Ovaries were collected in pairs from sows sourced from two farms and slaughtered 4 days after weaning during winter and summer. The mean progesterone concentration in follicular fluid (FF) collected from small follicles was lower in summer (701.3 ± 115.54 nm) compared with winter (1235.55 ± 164.47 nm; p < 0.001). The mean progesterone concentration in the FF of large follicles was also lower in summer (1469.2 ± 156.51 nm) compared with winter (2470.9 ± 169.13 nm; p < 0.001). The number of large surface antral follicles (5-8 mm in diameter) on the ovaries recovered from Farm A sows was higher during summer (17.76 ± 0.56) than in winter (15.38 ± 0.54; p < 0.05). Similarly, the number of small follicles (3-4 mm in diameter) on Farm A sow ovaries was higher in summer (8.46 ± 0.66) than in winter (4.63 ± 0.53; p < 0.001). In contrast, the number of small follicles on the surface of ovaries recovered from Farm B sows was higher during winter (10.17 ± 1.50) than in summer (6.45 ± 1.00; p < 0.01). The number of pre-ovulatory follicles (>8 mm in diameter) was also higher in winter (1.23 ± 1.68) when compared to summer (0.51 ± 0.3; p <0.001) on the ovaries of sows from Farm B. The results suggest that there are seasonal differences in follicular steroidogenesis and ovarian dynamics. These findings add support to the theory that altered follicular steroidogenesis and ovarian morphology may possibly be the mechanism behind reduced reproductive performance during the period of seasonal infertility in sows.
Objective Proliferative enteropathy (PE) of pigs is caused by Lawsonia intracellularis. Clinical severity appears to depend, at least partly, on the infective dose and strain of L. intracellularis. ...Serological tests are able to detect subclinical disease. The Bioscreen ELISA for detecting L. intracellularis‐specific antibodies is widely used to monitor the circulating antibody status of pigs in Australia, but its sensitivity and specificity have not been reported. The aim of the present study was to measure the seroprevalence of antibodies to L. intracellularis in growing pigs in Australia.
Methods Test sera were sourced from 1817 serum samples collected from finisher pigs from 63 herds across Australia in 2001, selected from a larger sample of 180 herds to represent the contribution that each herd size makes to the number of pigs produced. The test sera were the most recent collection of pig sera from all states and samples had been stored at −80°C from 2001 until testing was conducted in 2008. Sera were tested using the BioScreen ELISA.
Results All herds tested positive for L. intracellularis‐specific antibodies. The mean percentage of positive samples within each herd was 84.2% (range 31.3–100%).
Conclusions Lawsonia intracellularis is endemic in pig herds in Australia and cost‐effective strategies to reduce reliance on antibiotics, such as vaccination and/or all‐in/all‐out pig flow coupled with cleaning and disinfection of pens, are warranted.
Objective
To gather information on the demographics, motivations, marketing strategies and rearing techniques of producers who trade pigs at livestock markets in eastern Australia.
Methods
A 2‐page ...postal survey was administered to 815 pig producers trading pigs at six livestock markets in eastern Australia. Preliminary demographic and managerial practices were qualitatively and quantitatively determined. Logistic regression analysis was used to provide an insight to those practices that could pose a risk for exotic disease introduction and/or spread.
Results
A response rate of 68.7% (505 survey questionnaires) was achieved. Most respondents (73.1%) resided in regional areas and 65.5% of these were classed as ‘small‐scale’ (<100 sows). Herd size was significantly (P < 0.0001) associated with the use of veterinary services, with smaller herds less likely to consult a veterinarian. In addition, peri‐urban producers (24.8%) tended (P = 0.051) to contact veterinarians more frequently than regional producers (15.2%). Motivations for keeping pigs differed by herd size, nationality and producer type. One‐third of respondents trading pigs used more than one method to market pigs, with marketing strategies differing by herd size. Producers with smaller herd sizes kept pigs as a secondary source of income, as a hobby or for home consumption (P < 0.0001).
Conclusion
Key risk areas for exotic disease introduction and spread identified in this study included lack of veterinary contact, motivations for keeping pigs other than financial, marketing pigs privately with no formal transaction documentation and the co‐production of pigs with ruminant and domestic bird species.
Objective: To assess current swill feeding legislation, swill feeding investigation practices by authorities and feeding practices of pig producers who trade via saleyards in eastern Australia in ...order to determine levels of understanding and conformance related to current swill feeding legislation. Method: A three-tiered approach was undertaken to gather information on the feeding of prohibited substances (swill) to pigs in Australia. Firstly, a review of swill feeding legislation was undertaken to highlight the commonalities and inconsistencies between the various state and territory legislations in defining swill. Secondly, agricultural authorities were contacted in each state to gather information on swill feeding investigations undertaken in 2006. Finally, face-to-face interviews were conducted with 106 pig producers who traded pigs at one of six saleyards in eastern Australia to ascertain their knowledge of swill feeding and to determine the feeding practices of this sector of the industry. Results: Areas of concern identified included (1) inconsistencies in the feedstuffs classed as ‘swill’ among states, (2) the number of producers who had been prosecuted for swill feeding in 2006 (n = 4 of 148 inspections), (3) the low knowledge base of producers who sell pigs at saleyards regarding swill feeding, and (4) the types of feedstuffs provided to pigs marketed at saleyards. Conclusion: Our findings highlight the need for a consistent definition for ‘swill’ across Australian states and for improved awareness of swill feeding among producers, particularly those who market pigs at saleyards.
Proliferative enteropathy (PE) is an enteric disease of pigs that results in diarrhoea, reduced growth rate, reduced feed conversion efficiency and sometimes death. A survey of 13 pig veterinary ...practitioners in Australia was conducted to determine: (1) PE control strategies (antibiotics and vaccination), (2) how the efficacies of these strategies are evaluated and (3) how reliance on antibiotics could be reduced by increasing vaccine adoption. Antibiotics were routinely prescribed in the diets of weaner, grower and finisher pigs by 9/13, 10/13 and 8/13 veterinarians, respectively, if vaccination was not implemented. Water‐soluble antibiotics were prescribed less frequently than in‐feed antibiotics. Efficacy of control strategies was assessed most often through reduced clinical signs (diarrhoea, ‘tail‐ender’ pigs, death) and reduced lesion incidence at abattoir postmortem inspection. Twelve practitioners had recommended PE vaccination to their clients in the previous 6 months. Barriers to continued vaccine implementation included perceived lack of efficacy for pigs housed in bedded systems, high cost relative to medication and difficulties in vaccinating pigs post‐weaning.
