Evaluation of post-farm-gate passive surveillance in swine for the detection of foot and mouth disease in Australia

Pigs are considered high risk for the introduction and spread of foot and mouth disease (FMD) in Australia. One of the most likely pathways of introduction of FMD into Australia would be through the illegal importation of FMD-contaminated meat, which is then fed to feral or domestic pigs. Locations where animals from different origins are commingled, such as livestock markets and abattoirs, pose a risk for disease spread. Early detection of exotic diseases at these locations is crucial in limiting the spread of an outbreak. The aims of this study were to evaluate the likelihood of exotic disease detection with current passive disease surveillance activities for pigs at saleyards and abattoirs in eastern Australia, and make recommendations for improving surveillance. Sensitivity (Se) of the current post-farm-gate passive surveillance for detection of exotic diseases was estimated using the scenario tree modelling methodology (Martin et al., 2007a). Four surveillance system components were identified: (i) domestic saleyard, (ii) export saleyard, (iii) domestic abattoir, and (iv) export abattoir. Pig farms were classified according to herd size (Small vs. Large) and subsequently into two risk categories depending on the probability of swill feeding (Swill feeding vs. Not swill feeding). A scenario tree representing the pathways by which infected animals could be detected was developed and the Se of detection in each surveillance system component was estimated. Industry statistics, information on previous exotic disease outbreaks, and interviews with pig producers were used to estimate herd category proportions and the relative risk of swill feeding. Quantitative estimates for probabilities of detection were sourced from State legislation and policies, stakeholder consultation and observational studies at saleyards and abattoirs. Results of a FMD case study showed a Se of detection at a representative location for each surveillance system component during a 2-week period of 0.19 at domestic saleyards, 0.40 at export saleyards, 0.32 at domestic abattoirs and, 0.53 at export abattoirs. This output assumed the country was infected with herd and unit design prevalences of 1% and 30%, respectively. Improving disease awareness of saleyard and abattoir stockmen, increasing the presence of inspectors at these venues and identifying those herds posing a higher risk for FMD introduction, could improve the capacity of the country for early detection of emerging animal diseases.     

Assessment of the management practices facilitating the establishment and spread of exotic diseases of pigs in the Sydney region

OBJECTIVE: To assess management factors that would influence the establishment and spread of exotic diseases in pigs in the Sydney region. DESIGN: Saleyard and pig producer practices that could assist the initiation and subsequent spread of exotic diseases in pigs were surveyed and assessed over a 12 month period. PROCEDURE: Two saleyards in the Sydney region selling pigs were attended weekly for 12 months (2002-2003) to collect details on vendors and purchasers of pigs. Pig producer locations were mapped. All pig farmers on the Department of Primary Industries temporary brand register were surveyed to record management practices and knowledge of exotic diseases. Swine brands were inspected to determine their quality as a tracing mechanism. RESULTS: There were 101 pig sale days during the survey period with 13,869 pigs sold. There were 305 vendors, of whom 95% were identifiable through saleyard records. However, only 40% of the 377 purchasers were identifiable. More than one third of the 1749 transactions were for cash without the identity of the purchaser being recorded at the saleyards. Some 3% of pigs failed to sell and were returned to the property of origin. A total of 64 of 132 pig producers in the Sydney region were surveyed and 52 responded with survey information. The production systems of pig producers were predominately intensive or semi-intensive (88%) with 69% of these operators being small hobby producers. Pigs were mostly fed household and commercial scraps that were free of meat scraps, however, 2 producers were found to be feeding meat scraps (swill) illegally. Some 56% of producers surveyed did not have a tattoo swine brand and of the 23 producers with registered brands, 3 were not available for inspection or were not functional and 2 used the brand irregularly. CONCLUSION: This survey has identified factors that would assist the establishment and spread of vesicular and other exotic diseases in pigs. The factors included feeding meat scraps (swill), poor farmer knowledge of exotic diseases, ineffective pig owner identification at saleyards, the practice of cash sales that precluded the collection of purchaser details, and inadequate identification of pigs. Tracing the movements of pigs under these circumstances would be difficult.     

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.     

Biosecurity practices and the potential for exhibited pigs to consume swill at agricultural shows in Australia

Our objectives were to document the biosecurity practices implemented at agricultural shows in Australia and to measure the potential for pigs to consume swill at shows. An observational study was conducted at 6 agricultural shows in 2006 to identify the potential for pigs to consume swill. In addition, a questionnaire on biosecurity practices was distributed to administrative personnel responsible for 64 pig exhibits at 46 agricultural shows in Australia in 2005. A total of 153 feed exposure events were recorded during the 22-day observation period, of which 48 (31.3%) were identified as swill. Health status declarations for incoming pigs were required by 11.7% of exhibits. Exhibitors were solely responsible for monitoring the health of the pigs while at the show in 17 (28.3%) exhibits. Where agricultural show staff were responsible for health monitoring, only 2 of 60 respondents stated their staff had training in disease recognition. In 49 (83.1%) exhibits, pig manure was disposed outside of the showground. Our results demonstrate that current biosecurity practices at pig exhibits at agricultural shows in Australia may allow the introduction and dissemination of exotic diseases, particularly FMD.     

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.     

Use of stakeholder analysis to inform risk communication and extension strategies for improved biosecurity amongst small-scale pig producers

Extension and communication needs amongst small-scale pig producers, described as pig producers with less than 100 sows, have been previously identified. These producers, who are believed to pose a biosecurity risk to commercial livestock industries, are characterized by a lack of formal networks, mistrust of authorities, poor disease reporting behaviour and motivational diversity, and reliance on other producers, veterinarians and family for pig health and production advice. This paper applies stakeholder identification and analysis tools to determine stakeholders' influence and interest on pig producers' practices. Findings can inform a risk communication process and the development of an extension framework to increase producers' engagement with industry and their compliance with biosecurity standards and legislation in Australia. The process included identification of stakeholders, their issues of concerns regarding small-scale pig producers and biosecurity and their influence and interest in each of these issues. This exercise identified the capacity of different stakeholders to influence the outcomes for each issue and assessed their success or failure to do so. The disconnection identified between the level of interest and influence suggests that government and industry need to work with the small-scale pig producers and with those who have the capacity to influence them. Successful biosecurity risk management will depend on shared responsibility and building trust amongst stakeholders. Flow-on effects may include legitimating the importance of reporting and compliance systems and the co-management of risk. Compliance of small-scale pig producers with biosecurity industry standards and legislation will reduce the risks of entry and spread of exotic diseases in Australia.     

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.     

A description of local pig feeding systems in village smallholder farms of Western Kenya

We used face-to-face interviews to gather data on pig feeding practices in rural Busia District, Kenya. We visited 164 pig farms three times in the course of the study period. The pigs were weighed in kilograms during the visits. Feeds offered to pigs were described during the interviews. The most frequently fed feedstuffs were; ground maize or "ugali" (88%), kitchen leftovers (83%) and dried fish locally called "omena" (78%). Farmers provided pigs with water separately from the feeds. Sweet potatoes, "ugali" and cassava were available and could serve as good sources of energy for pigs in the district. Fruits and vegetables were also available and could potentially act as good sources of vitamins. Sweet potato vines, "omena" fish and slaughter blood were available and could provide pigs with proteins. The average daily gain (ADG) for pigs ≤ 5 months of age, pigs of 5.1-9.9 months of age and pigs of ≥ 10 months old was 94.5 (± 43), 127 (± 49.8) and 99 (± 92) g, respectively (p = 0.000). This study has outlined the different local pig feeds available in Busia district. We recommend two things: first, additional research on nutrient composition for the identified local feeds, and second, developing and validating simple local feed combinations that would achieve balanced local pig rations.     

Survey of internal parasites in Western Australian pig herds 2. Relationship to anthelmintic usage and parasite control practices

The housing, management and internal parasite control practices used in piggeries in Western Australia was surveyed by interviewing the owner/manager of 100 randomly selected piggeries. At the time of the interview 20 faecal samples were collected from pigs and examined for evidence of internal parasites. Most herds (80%) in which anthelmintics were used, had evidence of nematode infection. Some pig producers were using an anthelmintic that was ineffective against nematode species present while some herds had nematodes that should have been controlled by the anthelmintic being used. Prevalence of nematode infection was higher in pigs run in paddocks than in pigs housed intensively. Washing sows prior to farrowing was associated with a lower prevalence of nematode infection. The findings suggested that pig producers should ensure that the anthelmintic used is effective against the nematodes present in their pigs. It was concluded that administering anthelmintics as a single dose in the feed may not be the most effective method of deworming pigs.     

Feeding and performance of pigs in smallholder production systems in Northern Lao PDR

A survey was carried out in the North of Lao PDR to study feeding systems and the performance of pigs in smallholder systems. A total of 341 farmers from five provinces were interviewed. To feed their pigs, farmers mainly rely on feedstuffs produced on the farm and collected from areas near the village. The feedstuffs used included by-products such as rice bran and distiller’s waste, planted feeds, mainly maize and cassava, and various green plant materials. The feedstuffs used are usually high in energy and low in protein content, and the only readily available protein source is green plant material. This results in nutritionally imbalanced diets and as a result poor pig performance. The average growth rate of pigs in these systems was found to be only approximately 100 g/day. The reproductive performance of sows was found to be relatively low, as is the case of local breeds in the region, with an average litter size at birth of 6.8 piglets. The mortality of piglets was as high as 50% and was a main concern of farmers. In order to improve the productivity of pigs in smallholder systems, there is a need to find alternative feed resources to improve the nutritional feed quality, and to develop management systems which are suited to the needs and practices of smallholders.     

Impact of nutrition on nitrogen, phosphorus, Cu and Zn in pig manure, and on emissions of ammonia and odours

In order to reduce N, P and trace elements in pig manure, research toward a better agreement between supply and requirement has been undertaken in recent years, and ways to improve the biological availability of these elements in feedstuffs have been investigated. Substantial reduction in N excreted by pigs can be achieved by phase feeding combined with a better adjustment of the dietary amino acid balance. Feeding pigs with low N diets also allows a reduction of ammonia emission and to some extent the production of malodorous compounds. Phase feeding is also effective in reducing P excretion. However, low digestibility of P in feeds remains the main problem, although it is partly alleviated by the supplementation of pig diets with microbial phytase and the use of highly digestible mineral phosphates. In the same way, lowering Cu and Zn dietary supply is obviously an efficient way to reduce pigs' excretion of Cu and Zn. In a whole-farm perspective, improving the efficiency of nutrient utilisation by the animals is an efficient way to reduce import of nutrients from outside the farm and decrease the environmental risks.     

Pig producers' perceptions of the Influenza Pandemic H1N1/09 outbreak and its effect on their biosecurity practices in Australia

The Influenza Pandemic (H1N1/09) virus was first reported in humans in Mexico in April 2009 and a pandemic level was declared on 11th of June 2009 by the World Health Organization (Chan, 2009; WHO, 2009a). Public misconceptions about the transmission of H1N1/09 were caused by the inadequate naming of the disease as 'swine influenza'. This cross-sectional study was conducted at the height of the outbreak in the Australian human population and before the virus was reported in the first piggery in Australia in July 2009 (OIE, 2009b; Holyoake et al., 2011). The aims of this study were to evaluate pig producers' perceptions about the virus and the outbreak financial impact and influence on on-farm biosecurity practices. A questionnaire was designed and posted to Australian Pork Limited (APL) members (n=460), obtaining responses from 182 producers (39.6%). Pig producers had good general knowledge on potential transmission pathways for H1N1/09 between people, with direct or close contact with a sick person perceived as the most likely pathways. Changes on biosecurity practices, such as asking visitors if they had recently been overseas (27.8%) and not allowing any visitor to inspect their pigs (18.3%), were reported among respondents. In addition, approximately 40% of producers asked their employees to notify flu like symptoms, consulted a veterinarian on H1N1/09 and visited websites to seek information on H1N1/09. A higher adoption of these practices was observed among large (>100 sows) than small herds. Only 2.9% of respondents reported a reduction in pig sales during the outbreak. However, approximately one third of producers reported being financially and emotionally stressed, 38.2% were distressed about the health of their pigs and 16.7% about their own health. The most important sources of information were APL (93%), veterinarians (89%) and the state Department of Primary Industries (DPI) (75%). The first two considered the most trusted sources of information. Television, radio and other farmers were considered more important sources of information by small herds and veterinarians by larger herds. Producers believed that the H1N1/09 outbreak was better managed by the pork industry (89.9%) than by the health authorities (58.8%), and the on-going communication with APL was the main strength of the outbreak management. Communication and extension programs in future outbreaks should consider the needs of all sectors of the pig industry to increase their effectiveness.     

Assessment of current disease surveillance activities for pigs post-farmgate in New South Wales

Objectives Evaluate current disease surveillance activities at saleyards and abattoirs in New South Wales (NSW) in order to establish the prevalence of clinical anomalies in pigs at different sites and to compare the sensitivity of detecting anomalies inside versus outside of pens. Procedure Routine inspections of pigs by staff and government inspectors were observed at two saleyards and two abattoirs in NSW during three visits over a 2-month period (January 2008–March 2008). All pigs presented for sale or slaughter were examined for 19 clinical anomalies from either the side of the pen or while animals were moving outside the pen, with data being combined to give an assumed ‘gold standard’. We compared the prevalence of anomalies among animals at the four sites using logistic regression, as well as the sensitivity of detection of the two inspection methods. Results Frequency and methodology of routine inspection varied among sites. Of the 7747 pigs inspected, 822 (10.6%) showed at least one clinical anomaly. There was moderate agreement between detecting anomalies in penned pigs versus while being moved. Pigs at one abattoir exhibited significantly fewer anomalies than pigs at the other sites. Conclusion The prevalence of anomalies among pigs at saleyards and abattoirs in NSW was relatively high (≈10%). Weaknesses in current disease surveillance activities for pigs post-farmgate have been identified. Increased regulation, surveillance training and modification of standard operational procedures for inspection have the potential to improve the current system.     

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.     

Risk factors of African swine fever virus in suspected infected pigs in smallholder farming systems in South-Kivu province,Democratic Republic of Congo

BackgroundAfrican swine fever (ASF) is an infectious viral disease of domestic pigs that presents as a hemorrhagic fever, and for which no effective vaccine is available. The disease has a serious negative social and economic impact on pig keepers. There is limited information on the potential risk factors responsible for the spread of ASF in South Kivu.ObjectiveThe aim of this study was to determine the potential risk factors associated with ASF infection in suspected ASF virus (ASFV)-infected pigs.MethodsWe sampled whole blood from 391 pigs. Additionally, 300 pig farmers were interviewed using a structured questionnaire. Viral DNA was detected by using the real-time polymerase chain reaction technique.ResultsThe majority of pigs sampled, 78% (95% confidence interval [CI], 74.4–82.6), were of local breeds. Over half, 60.4% (95% CI, 55.5–65.2), were female, and most of them, 90.5% (95% CI, 87.6–93.4), were adult pigs (> 1 year old). Viral DNA was detected in 72 of the 391 sampled pigs, indicating an overall infection rate of 18.4% (95% CI, 14.5–22.4). Multivariable logistic regression analysis revealed several risk factors positively associated with ASFV infection: feeding with swill in pen (odds ratio [OR], 3.8; 95% CI, 2.12–6.77); mixed ages of pigs in the same pen (OR, 3.3; 95% CI, 1.99–5.57); introduction of new animals to the farm (OR, 5.4; 95% CI, 1.91–15.28). The risk factors that were negatively (protective) correlated with ASFV positivity were the presence of male animals and the use of an in-pen breeding system.ConclusionLocal pig farmers should be encouraged to adopt proper husbandry and feeding practices in order to increase the number of ASF-free farms.     

Technical note: Evaluation of the official identification system for pigs for sale in New South Wales

A study was undertaken at 2 saleyard (1 domestic, DS, and 1 export, ES) and 2 abattoir (1 domestic, DA, and 1 export, EA) locations in New South Wales, Australia, to assess the compliance (presence) and readability of body tattoos used to identify individual pigs presented for sale or slaughter. Each location was visited on 3 trading or slaughter days, and tattoo presence and readability of porkers (25 to 60 kg of BW), baconers (60 to 90 kg of BW), backfatters (>90 kg of BW but not for breeding), and breeders were recorded. A total of 4,655 pigs were inspected, including 158 DS, 1,599 ES, 1,257 DA, and 1,641 EA. Tattoo performance at the saleyards was influenced by producer (P < 0.05). Average brand presence at the DS (93.0%) did not differ (P = 0.28) from ES (74.2%). Tattoo compliance ranged from 88.3 to 100% of pigs across pig classes (P > 0.05) at DS. At the ES, tattoo compliance among baconers, backfatters, and breeding stock ranged from 82.4 to 88.3% and was greater (P < 0.05) than that of porkers (70.3%). Average readability was 85.4% at ES and 77.6% at DS (P > 0.05). Tattoo compliance differed (P < 0.05) between abattoirs (98.7% at DA and 92.6% at EA). Readability was greater (P < 0.05) at the EA (80.1%) than at the DA (72.0%). Final performance, as readable brands among animals sold or slaughtered, of the official tattoo system was similar between locations and ranged from 63 to 74%. Our results suggest that current compliance and readability of tattoos would compromise traceback to the farm of origin in the event of an emergency animal disease outbreak. Education activities on legislation requirements and tattoo procedure would likely increase compliance and performance of the system.     

Prevalence of proliferative enteritis on pig farms in Australia

SUMMARY 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.     

Risk factors for porcine reproductive and respiratory syndrome outbreaks in Vietnamese small stock farms

AIM: To examine risk factors that could have played a role in the 2010 porcine reproductive and respiratory syndrome (PRRS) outbreak in Yenhung district, Quangninh province, North-Vietnam, with the purpose of establishing why existing control measures implemented after previous outbreaks had failed to prevent further outbreaks.

METHODS: A case-control study was carried out in Yenhung district. Data were obtained by an interview-based questionnaire survey. The sampling unit was households, which equated to small-scale pig farms. A total of 150 case and 150 control households were selected at communes affected by the 2010 PRRS epidemic during April to June. Risk factors were analysed using binary logistic regression and unconditional multiple logistic regression.

RESULTS: Households infected with PRRS were significantly associated with multiple variables belonging to three main groups: (1) location of the farms: i.e. farms positioned <1,000?m from a pig abattoir or within 500?m of local markets or 100?m of main roads; (2) farm management: i.e. where there was non-application of weekly farm disinfection, feeding uncooked swill, new introduction of purchased pigs without isolation, or usage of water from irrigation systems for raising pigs; (3) people and animal contact: i.e. where households kept animals with either no confinement or partial confinement, had visits by family members to other affected farms or had frequent visits by neighbours. The use of water from irrigation systems was found to be the risk factor most strongly associated with infected households in the 2010 outbreak (OR=22; 95% CI=12–42).

CONCLUSIONS: The results show that the epidemiology of PRRS in Quangninh province was linked to sociological and cultural practices, and that effective PRRS control needs an integrated approach coupled with behavioural changes in the pig raising practices of the general public. Failure to recognise this could explain why further outbreaks have occurred.     

In vitro analyses for predicting standardised ileal digestibility of protein and amino acids in actual batches of feedstuffs and diets for pigs

In vitro digestibility analyses of feedstuffs and diets are integrated in the new Danish feed evaluation system for pigs. This system is based on potential physiological energy and standardised digestible amino acids. For characterisation of the energy value of actual batches of feedstuffs and complete diets for pigs, two different in vitro methods have been developed and proved to analyse precisely the digestibility of organic matter at faecal, as well as at ileal, level in the pigs. For characterisation of the protein value in the diet, table values for standardised digestibility of amino acids from the individual feedstuffs are used for calculation of their contribution to the amino acid recommendations for the specific pig category. The results in the present paper indicate that in vitro analyses for digestibility of crude protein in feedstuffs are a reliable tool for calculation of standardised ileal digestibility of the individual amino acids. Thus, the results may question the need for future experiments with surgically modified pigs for analysing ileal digestibility of amino acids in protein sources. Alternatively, in vitro digestibility analyses appear to have a general potential for a precise evaluation of amino acid digestibility in actual batches of feedstuffs and pig diets.