Seasonal variation in the ovarian function of sows.

The modern domestic sow exhibits a period of impaired reproductive performance known as seasonal infertility during the late summer and early autumn months. A reduction in farrowing rate due to pregnancy loss is the most economically significant manifestation of this phenomenon. Presently, little is known of the aetiology of seasonal pregnancy loss in the pig. Recent findings represent a major advancement in the understanding of sow reproductive physiology and implicate poor oocyte developmental competence as a contributing factor to pregnancy loss during the seasonal infertility period. It has also been demonstrated that ovarian activity is depressed during the seasonal infertility period. The reduction in oocyte quality is associated with decreased levels of progesterone in follicular fluid during final oocyte maturation in vivo. The recent identification of sow-specific risk factors, such as parity for late pregnancy loss, should improve breeding herd efficiency by allowing producers to tailor management interventions and/or culling protocols that target animals identified as having a greater risk of late pregnancy loss during the seasonal infertility period.

Follicular progesterone levels decrease during the period of seasonal infertility in sows.

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.

Oocyte developmental competence is reduced in sows during the seasonal infertility period.

The modern domestic sow exhibits a period of impaired reproductive performance during the late summer and early autumn months, known as 'seasonal infertility'. A reduction in farrowing rate due to pregnancy loss is the most economically important manifestation of seasonal infertility. The aim of the present study was to determine whether there are changes in oocyte developmental competence associated with season. Ovaries were collected in pairs from sows sourced from commercial piggeries and slaughtered 4 days after weaning during winter and summer-autumn. Following oocyte IVM and parthenogenetic activation, the ability of oocytes from large follicles to form blastocysts was greater in winter (54.94 ± 6.11%) than in summer (21.09 ± 5.59%). During winter, the proportion of oocytes developing to the blastocyst stage from large follicles was significantly higher (54.94 ± 6.11%) than those oocytes from small follicles (23.17 ± 6.02%). There was no effect of season on the proportion of oocytes developing to the blastocyst stage from small follicles. There was no effect of follicle size on blastocyst formation from those oocytes recovered during summer. Blastocysts derived from small follicles during summer had the lowest number of cells (24.25 ± 1.48) compared with blastocysts derived from large follicles during winter (37.5 ± 1.3; P < 0.05). The mean progesterone concentration in follicular fluid collected from small follicles was greater in winter than summer (1235.55 ± 164.47 v. 701.3 ± 115.5 nmol L(-1), respectively; P < 0.001). The mean progesterone concentration in the follicular fluid of large follicles was also greater in winter than in summer (2470.9 ± 169.1 v. 1469.2 ± 156.5 nmol L(-1), respectively; P < 0.001). Regression analysis revealed a positive correlation between progesterone concentration and oocyte developmental competence. The results indicate that porcine oocytes fail to reach their full developmental potential during the period of seasonal infertility, suggesting that the pregnancy losses observed at this time of year may be due to reduced oocyte developmental competence.

Challenges posed to the traceability of weaner pigs following live auction.

OBJECTIVES: To gather demographic data on live pig sales through a peri-urban saleyard in Camden, New South Wales, and to demonstrate the difficulties in tracing the subsequent movements of pigs, particularly weaner pigs. PROCEDURE: Records of pig sales held weekly at the Camden saleyards for the 2003/2004 and 2004/2005 financial years were analysed. Saleyard data on a number of variables were entered into a purpose-designed database. Distributions of pig sales according to pig class (weaner/porker/baconer/backfatter), purchaser type (butcher/non-butcher), and transaction type (cash/account) were determined. RESULTS: More weaners (3192 in 2003/2004 and 3940 in 2004/2005) were sold than any other class of pig, accounting for 45% of the total pigs sold during this period. During 2003/2004, 3802 pigs were bought by 329 non-butcher purchasers including 1631 weaners (43%) purchased by 153 non-butchers (47%). The majority of these non-butchers during the study period (86%) paid cash for their pigs and did not provide the necessary information to allow the end destination of pigs to be determined. Location data was available for all vendors but only 25% of purchasers. CONCLUSIONS: This study highlights the challenges posed in tracing movement of pigs following sale by auction. A high proportion of weaners sold at this peri-urban saleyard would not have been slaughtered immediately. This study highlights the potential difficulties in tracing pig movements after sale, for disease control purposes. We recommend that legislation be amended requiring the identification of weaner pigs sold live at auction in all states of Australia and the recording of the property identification code of all vendors and purchasers of pigs sold live at auction.

Identifying obstacles to reducing the use of antibiotics to control porcine proliferative enteropathy.

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.

Review of identification and traceability legislation for pigs in Australia.

OBJECTIVE: To assess Australia's capability to trace pig movements in the event of an exotic disease outbreak by highlighting the commonalities and inconsistencies between the various state and territory legislations in defining how pig producers are located; their pigs are identified; and whether movement records are required post-farm gate. PROCEDURE: A review of the identification and traceability legislation applicable to pigs in Australia was undertaken over a 6 month period. The appropriate legislative Acts and Regulations were downloaded from the Australasian Legal Information Institute internet site (http://www.austlii.edu.au/) and reviewed. RESULTS: The Australian pig industry currently uses the branding method (tattooing) to identify pigs for sale or slaughter, with each state responsible for its own pig identification and movement control systems. Areas of concern identified included inconsistencies with the minimum weight or age of pigs that require identification; discrepancies between methods of tattoo registration and shortfalls in documentation for recording pig movements. CONCLUSION: Our findings highlight the flaws in Australia's current state legislative Acts and Regulations for identifying pigs and tracking their movements, which compromise the ability of jurisdictions to meet the endorsed National Performance Standards. Improvements in these areas will enhance security to the pig and other livestock industries in the event of future exotic disease outbreaks.

Isolation of [Actinobacillus] rossii from an aborted piglet.

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.

The occurrence of congenital heart defects in an inbred herd of pigs in Australia.

OBJECTIVE: To report on the first case of congenital heart defects in pigs in Australia. DESIGN: Retrospective analysis of case records from an inbred herd of "Westran" pigs at the University of Sydney, between January 2001 and December 2004. Detailed gross and histological examination of 15 hearts from pigs that had died or were euthanased in 2004. CASE DETAILS: The necropsy records from a population of 471 pigs that had died (106 pigs) or were euthanased for research purposes (365 pigs) were analysed and the incidence of heart defects recorded, together with basic demographic data. No attempts were made to diagnose the condition in live pigs. RESULTS: Congenital heart defects were diagnosed in 6.4% of pigs but this is likely to be an underestimate of the incidence of the deformity. Eighteen pigs died on the farm as a result of the defect, and 12 pigs were diagnosed with the defect as an incidental finding. The most common abnormality seen at necropsy was a sac-like dilatation on the right lateral surface of the right atrium. This was associated with secondary deformity and hypoplasia of the adjacent left ventricle, interventricular region and part of the right ventricle. All hearts showed atrial septal defects of varying size. CONCLUSION: This is the first reported case of congenital heart defects in pigs in Australia, and one of less than five reported cases of atrial septal defects in pigs in the world. The authors conclude that there may be an element of genetic predisposition to the malformation, since it has only been reported in this inbred line of pigs.

On-farm characteristics and biosecurity protocols for small-scale swine producers in eastern Australia.

Pigs are considered high risk for the introduction and spread of foot and mouth disease (FMD) in Australia. Facilities where animals from different origins are commingled, such as saleyards, pose a high risk for disease spread. Sound on-farm management practices and biosecurity protocols are the first line of defence against a potential on-farm disease outbreak. This study evaluated the practices of 104 producers (vendors who sold pigs and purchasers of live pigs for grow-out) who traded pigs at 6 peri-urban and rural saleyards in eastern Australia. Specifically, management and on-farm biosecurity practices were assessed using an in-depth questionnaire. Univariable and multivariable logistic regression analyses were used to investigate (1) producer associations: producer type, State, motivation to keep pigs, farm type, gender, years having owned pigs, and the acquisition of formal livestock qualifications; and (2) pig associations: herd size, housing, management (husbandry and feeding) practices and biosecurity (including pig movement) practices. Backyard operations (<20 sows) were undertaken by 60.6% of participants, followed by small-scale pig operations (28.8%; 21-100 sows). Few producers (16.3%) reported residing in close proximity (<5 km) to commercial operations; however, less rural producers had neighbouring hobby pig operations within 5 km of their property (P=0.033). Motivation for keeping pigs was significantly associated with a number of biosecurity practices. Producers who kept pigs for primary income were more likely to provide footwear precautions (P=0.007) and ask visitors about prior pig contacts (P=0.004). Approximately 40% of backyard and small-scale producers reported not having any quarantine practices in place for incoming pigs, compared to only 9.1% among larger producers. The main reasons cited for not adopting on-farm biosecurity practices in this study included having no need on their property (43.1%) and a lack of information and support (by the industry and/or authorities; 18.5%). Up to three-quarters of all producers maintained an open breeding herd, regularly introducing new pigs to the main herd. Saleyards are an important source of income for backyard and small-scale producers as well as an important risk factor for the introduction and dissemination of endemic and emerging animal diseases. Differing management and biosecurity practices as well as the motivations of these producers keeping pigs in small numbers and trading pigs at saleyards need to be taken into account in the development of successful biosecurity extension programmes for this sector of the Australian pork industry.

Application of a polymerase chain reaction assay for detection of proliferative enteritis-affected swine herds.

A polymerase chain reaction (PCR) assay was used to confirm the presence of ileal symbiont (IS) intracellularis in 3 swine herds with a history of proliferative enteritis (PE). Two pooled fecal specimens, each comprising 5 individual stool samples, were collected from pen floors to screen for the presence of IS intracellularis and determine the age range of pigs shedding the organism. IS intracellularis was detected in the feces of clinically normal 10-25-week-old grower/finisher pigs, indicating that this age range of pigs was the main source of infection for younger nursery pigs. Shedding continued without clinical disease when 10-100 g/ton of tylosin or 10 g/ton of chlortetracycline was added to the feed. PCR testing of pooled fecal samples can be used to identify groups of pigs affected with PE. The results of this study indicate that this PCR assay has the potential to accurately assess the IS intracellularis infection status of swine herds and the association of IS intracellularis with PE and growth performance.

Reducing pig mortality through supervision during the perinatal period.

A study was undertaken on a commercial swine farm to investigate methods of reducing perinatal mortality. During a 12-wk period, 251 sows and gilts were assigned randomly to one of four treatment groups in a 2 x 2 factorial design: 1) supervised/induced, 2) supervised/non-induced, 3) unsupervised/induced, and 4) unsupervised/non-induced. Supervised groups of sows and their litter were observed constantly for a minimum of 3 h before and until 3 d after farrowing. The onset of farrowing was induced with 250 micrograms of cloprostenol administered into the vulvo-vestibular mucosa. There was an increase (P = .012) in the number of pigs weaned from supervised (10.17 pigs/litter) relative to unsupervised group (9.44 pigs/litter). This increase was due to a reduction (P = .001) in both the number of stillborn pigs and the mortality of live-born pigs (P = .026). The latter resulted from fewer pigs that died (P = .003). Induction did not influence the mortality of pigs in the perinatal period in unsupervised groups. Induced sows farrowed an average of .43 d earlier than non-induced sows (P = .029). The mean interval from prostaglandin treatment to farrowing was 23.87 h (SD = 10.96). The results of this study suggest that a controlled farrowing system, coupled with good supervision, can improve pig survival. Financial analyses, based on improvements in pig survival resulting from additional labor in the farrowing house, suggested that this method of reducing preweaning mortality is a viable option for improving the profitability of commercial pig farms.

Outbreaks of proliferative haemorrhagic enteropathy on two pig farms.

Clinical signs of proliferative haemorrhagic enteropathy (PHE) including anaemia, dysentery and sudden death were observed in finisher pigs and young breeding stock on 2 farms. On farm A, PHE occurred 12 months after repopulation of the farm. Other outbreaks of PHE occurred after the withdrawal of therapeutic concentrations of in-feed antibacterial agents (farm A), or after monensin sodium (100 g/t) replaced olaquindox (100 g/t) in feed (farm B). The outbreaks, the possible sources of contamination and the role of antibacterial feed additives in the treatment and control of PHE are described.

Prevalence of proliferative enteritis on pig farms in Australia.

Three surveys, undertaken to assess the prevalence of proliferative enteritis (PE) on pig farms in Australia and to investigate risk factors associated with clinical disease, indicated that PE was a common disease in pig farms. Forty of the 71 (56%) randomly-selected producers had either observed PE or had a veterinarian diagnose the disease in their herd during 1988 to 1990. A relatively low prevalence of the disease was recorded at veterinary diagnostic laboratories, and this suggested that diagnoses of PE were often not confirmed by histopathological examination of the intestines of affected pigs. Non-haemorrhagic PE occurred most often in six- to 24-week-old pigs, but was also reported in 52-week-old pigs. Proliferative haemorrhagic enteropathy usually affected pigs over 16 weeks of age, but was also reported in pigs as young as six weeks and as old as four years of age. A survey of pig-specialist veterinarians indicated that most veterinarians diagnosed PE based on clinical and gross pathological examination of affected pigs, without laboratory confirmation. There were difficulties associated with measuring the prevalence of PE among herds, including the effectiveness of antibacterials for its prevention and control, its subclinical nature and probable mis-diagnoses. This study highlighted the need for an ante-mortem diagnostic test to measure the prevalence of PE more accurately.

Simulation of the economic impact of proliferative enteritis on pig production in Australia.

The economic impact of proliferative enteritis (PE) on an 'average' pig farm was calculated using the AUSPIG decision support system. Inputs were modelled on actual cases of PE, in which affected herds suffered from depressed growth rate, decreased feed efficiency and stock losses. The costs associated with non-haemorrhagic PE and proliferative haemorrhagic enteropathy ranged from $15/sow/yr to $141/sow/yr, respectively, depending on the clinical severity of the disease, incidence of infection and the type of medication strategy used to treat and control the disease.

The effects of reducing the length of canine teeth in sucking pigs by clipping or grinding.

OBJECTIVE: To provide production data that would support or discount current teeth clipping practices in sucking pigs. DESIGN: Intervention study of 207 litters of pigs on a commercial farm. PROCEDURE: Litters were assigned to one of three interventions undertaken at 1 day of age: clipped using hand-operated side cutter pliers, ground using a battery-operated grinder or left intact. The effects of the intervention on weaning weight, preweaning mortality, facial lesions, gum damage and arthritis in litters of pigs were recorded, as was the incidence of udder damage of the sows. Weight gain and facial damage postweaning of pigs within each intervention group were recorded. The cost:benefit of each intervention was determined. RESULTS: Average weaning weight of pigs whose teeth were clipped was higher than of those whose teeth were ground but not of those with intact teeth. Clipping resulted in fewer preweaning deaths than both unclipped and ground litters due to fewer overlays. The incidence and severity of face scarring was higher in unclipped litters than clipped and ground litters. Treatment had no effect on face scars at weaning, udder damage, post-treatment fostering, time of preweaning deaths or postweaning weight gain. There was an additional labour cost of 6 cents per pig with teeth clipping. CONCLUSION: This study supports teeth clipping of sucking pigs because there are welfare, production and financial benefits including reduced facial damage and preweaning mortality.

A national serological survey to verify Australia's freedom from porcine reproductive and respiratory syndrome.

OBJECTIVE: To provide serological data to support Australia's claim of freedom from porcine reproductive and respiratory syndrome. DESIGN: A national serological survey was designed to provide 99% confidence of detecting at least one infected pig herd in Australia, assuming that at least 5% of herds would have been exposed to porcine reproductive and respiratory syndrome virus and that at least 25% of the 'finisher' pigs in these herds would have antibodies to the virus. PROCEDURE: A two-stage testing regime was used. All samples were tested with a commercially available enzyme-linked immunosorbent assay. If assay reactions were found, all samples from the herd were to be tested using the indirect immunofluorescence antibody assay. RESULTS: Of the 875 samples from 163 herds from all States in Australia, there was some evidence of reactivity in only four samples from four herds on the enzyme-linked immunosorbent assay. Further testing using the indirect immunofluorescence antibody assay according to the study protocol demonstrated that the reactions were not due to the presence of specific porcine reproductive and respiratory syndrome virus antibodies in the sera. CONCLUSION: The results of this study support the view that Australian pigs are free of porcine reproductive and respiratory syndrome virus.

Investigating risk factors and possible infectious aetiologies of mummified fetuses on a large piggery in Australia.

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.

Building a picture: Prioritisation of exotic diseases for the pig industry in Australia using multi-criteria decision analysis.

Diseases that are exotic to the pig industry in Australia were prioritised using a multi-criteria decision analysis framework that incorporated weights of importance for a range of criteria important to industry stakeholders. Measurements were collected for each disease for nine criteria that described potential disease impacts. A total score was calculated for each disease using a weighted sum value function that aggregated the nine disease criterion measurements and weights of importance for the criteria that were previously elicited from two groups of industry stakeholders. One stakeholder group placed most value on the impacts of disease on livestock, and one group placed more value on the zoonotic impacts of diseases. Prioritisation lists ordered by disease score were produced for both of these groups. Vesicular diseases were found to have the highest priority for the group valuing disease impacts on livestock, followed by acute forms of African and classical swine fever, then highly pathogenic porcine reproductive and respiratory syndrome. The group who valued zoonotic disease impacts prioritised rabies, followed by Japanese encephalitis, Eastern equine encephalitis and Nipah virus, interspersed with vesicular diseases. The multi-criteria framework used in this study systematically prioritised diseases using a multi-attribute theory based technique that provided transparency and repeatability in the process. Flexibility of the framework was demonstrated by aggregating the criterion weights from more than one stakeholder group with the disease measurements for the criteria. This technique allowed industry stakeholders to be active in resource allocation for their industry without the need to be disease experts. We believe it is the first prioritisation of livestock diseases using values provided by industry stakeholders. The prioritisation lists will be used by industry stakeholders to identify diseases for further risk analysis and disease spread modelling to understand biosecurity risks to this industry.

Managing animal wellbeing: a preliminary survey of pig farmers.

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.

Demographic and production practices of pig producers trading at saleyards in eastern Australia.

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.