By David Burrows

It was August 2018 when China notified the World Organisation for Animal Health that African Swine Fever (ASF) was in the country. By September 2020, twelve countries in the EU had ASF cases, including Germany, one of the biggest exporters of pork in the world. “It’s very concerning,” says Rebecca Veale, senior policy advisor at the UK’s National Pig Association (NPA).

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This is a deadly virus that can kill almost 100% of the animals it infects. By mid-2019 around a third of the Chinese herd (150 to 200 million pigs) were thought to have been infected (though some forecasts put the figure far higher). The Food and Agriculture Organization (FAO) has called ASF a “global threat to animal health and food security with negative socio-economic impacts”.

There is no vaccine for ASF. It’s a remarkably robust virus, surviving in the environment or in processed meat for weeks and months, or longer on frozen meat. The biggest threat to the pig herds in Ireland and the UK is therefore infected meat products slipping across the border. It could arrive in contaminated meat, or on the boots of travellers or tyres of vehicles. Traces of the virus were found in samples of illegal meat products seized by port officials in Northern Ireland last year.

The UK farming minister George Eustice said in September 2020 to expect ASF “within a year”. The NPA reckons it’s probably already here. “It’s just whether that chance event would happen,” explained Zoe Davies, the NPA’s Chief Executive in an interview with The Guardian last year, “that somebody would go out into the countryside, and either put [contaminated meat] in a bin or chuck something over a hedge that the pigs got access to.”

Though presenting a severe food security and animal health threat, it is important to note that the virus is “harmless to humans”, according to the European Food Safety Authority (though the FAO has raised concerns about the impact on livelihoods, especially vulnerable subsistence farmers). A recent paper by experts at Friedrich-Loeffler-Institut in Germany, published in Virus Research, noted that ASF has “no zoonotic potential and there are no indications that this might change”.

But this might not matter to consumers if (or when) ASF arrives. Research in the US showed that, even after being provided information about why this is not a public health concern, more than half those surveyed said they’d stop eating pork if ASF was found there.

 

Feed for thought

It has been 12 years since the Irish pork sector suffered a major food safety scare: in December 2008 Irish pork products were withdrawn from sale across Europe as a precautionary measure after some products were found to be contaminated with dioxins and dioxin-like polychlorinated biphenyls at levels of toxicological concern. The reaction was swift and the country was “back in business within a week”, noted the Food Safety Authority of Ireland (FSAI) technical team in a 2009 paper.

The incident brought about a number of changes in approach, as well as increased capacity and capability across the island’s testing laboratories. Animal feed, which was found to be at the heart of the dioxin contamination, remains an area of concern for FSAI officials. “It’s vulnerable,” says Ray Ellard, the authority’s director of risk management and regulatory affairs. Contamination can get into the chain “unwittingly and unknowingly” and  “can be everywhere” very quickly. That said, the number of RASFF notifications regarding dioxins and dioxin-like PCBs in feed is “at its lowest level for the last 10 years” noted the Irish Grain and Feed Association in its February 2020 newsletter.

Intelligence has become a crucial element of FSAI’s work, while collaboration across Europe helps to pinpoint issues rapidly. A recent case in point involved chilled cooked pork. On 4 July 2019, Ireland issued an urgent inquiry reporting a cluster of cases of Salmonella Bredeney, and cases followed in the UK. On 15 July Ireland transmitted an alert via the EU’s Rapid Alert System for Food and Feed (RASFF) with evidence that products from Romania were the likely cause and within days the Romanian producer was suspended in order to sanitise and disinfect its premises.

 

Salmonella and other concerns

Salmonella remains the pathogen of most concern in terms of public health (Trichinella has not been reported for over 30 years so the risk posed is very minimal, according to the UK’s Agriculture and Horticulture Development Board (AHDB)). Salmonella was the most frequently reported pathogen in food (not just pig meat) from member states in 2019 (371 notifications, up by 51%). Nearly one in three foodborne outbreaks in the EU in 2018 were caused by Salmonella. Care taken in washing hands and cooking meat properly minimises the risks, but it’s still a big issue on farms, in particular those housing pigs.

In Ireland, Salmonella has been detected on pig carcasses in just over 50% of holdings with breeding pigs. Public health concern stems from bacteria being passed to weaning and fattener pigs, with the meat then becoming contaminated. It’s proved a difficult bug to control, and its prevalence doesn’t often follow scientific logic: ‘dirtier’ farms for example can be completely free of Salmonella. “Enigmatic” is the term used by Ciarán Carroll, head of knowledge transfer at the pig development department in Teagasc. While the considerable effort put into the National Pig Salmonella Control Programme for example, has resulted in lower rates of Salmonella carriage and carcass contamination rates, it hasn’t lowered them sufficiently, says Carroll. Work is currently underway to look at potential low-cost interventions on farms. The research involves 60 holdings in Ireland to identify those with ‘high prevalence’ and ‘low to zero prevalence’ and the management practices that are having an impact.

There is also an EU project underway under the ‘One Health European Joint Programme’ that aims to bring together expertise and research to focus on biosecurity interventions that can reduce Salmonella and Hepatitis E Virus (HEV) – another pathogen which can potentially prove fatal to humans, but like Salmonella is generally subclinical in pigs. HEV is a topic that’s actively monitored and discussed within the food safety subgroup of the Pig Health and Welfare Council, according to the UK’s AHDB.

A new European research project, coordinated by the German Federal Institute for Risk Assessment, is looking at approaches to reduce the occurrence of HEV and Salmonella on European pig farms. Biopigee, or ‘Biosecurity practices for pig farming across Europe’, will determine the best methods for containing these pathogens. The UK Animal and Plant Health Agency (APHA) hopes to make the outcomes relevant to both Porcine Reproductive and Respiratory Syndrome Virus (PRRS) and ASF.

PRRS is not a pathogen of public health concern as it is not transmissible to humans either directly from live pigs or indirectly from their meat/products, according to APHA.  However, it’s the most costly disease affecting pigs (costing the equivalent of £1.3bn in the EU). The virus can get onto farms in a number of ways, from bringing new animals into a system, to contaminated vehicles and equipment, people, biting flies and wildlife, explained Pig World in 2018. Vaccinations are available but biosecurity is also key.

 

Food waste scrap

Maintaining high levels of biosecurity on farms will be crucial in keeping ASF at bay too. There are concerns that one possible route into the UK or Irish pig herd is hobby farmers feeding scraps to their pigs. The Irish Pig Society receives numerous enquiries regarding the rules of feeding household scraps. The law is clear: this isn’t permitted. “The rules were put in place for a very good reason,” says NPA’s Veale.

This was of course due to the foot and mouth disease (FMD) epidemic some years ago. Indeed, though food waste is the archetypal pig feed, if it contains meat wastes and is not heat-treated it can transmit diseases like FMD and ASF. Research has shown that feeding food waste to pigs has a lower environmental impact than composting it or sending it to anaerobic digestors. However, as experts put it in a paper for the Journal of Cleaner Production in 2017 re-legalisation will require support from policy makers, the public, and the pig industry, as well as investment in separated food waste collection.

There is very little appetite seemingly for the rules to change anytime soon.  “To the consumer eye this would look to be a great opportunity to reduce waste from manufacturing,” notes AHDB, but “there currently isn’t any retail demand for this product”. Still, there are experts looking at this - the Waste and Resources Action Programme in the UK together with farming representatives are scoping out ways to use more food waste in the supply chain whilst maintain food safety and traceability. It’s at a “very early stage”, notes Veale.

 

Systems under strain

Why rock the boat? Trust in the EU food system jumped in 2020, according to the latest EIT TrustTracker, which involves 19,800 people in 18 countries. Some 55% of consumers think food products are generally safe (in Ireland it was around 70%). Trust has been rising since 2018 but there is “much still to be done to increase confidence” the January 2021 report reads.8732550693?profile=RESIZE_584x

The pandemic has played a part in this trust bump – citizens are grateful to the sector for keeping their cupboards stocked. However, it does bring risks too. Experts have warned of another  ‘horsemeat scandal’ given the immense strain supply chains are under. This is heightened in pork: an outbreak of covid-19 at an abattoir in north east Scotland recently saw farmers faced with finding accommodation for two weeks’ worth of finished pigs.

ASF adds another strain. Professor Chris Elliott from the Institute of Global Food security at Queen’s University Belfast recently warned that fraud in pork supply chains was a very real threat as supplies tightened. Fluctuating commodity prices represented an “opportunity” for fraudsters, he told The Grocer.

Covid has also placed a spotlight on meat production, especially the industrial end of the scale. Livestock production was already under considerable strain thanks to its heavy environmental impact so pressure to rethink systems will increase. Intensification of farms has also seen use of antibiotics rise and with it concerns about antimicrobial resistance (AMR). As James O’Neill put it in his review of AMR for the UK government, published in 2016, “large numbers of animals living in close proximity, or in non-hygienic conditions can act as a reservoir of resistance and accelerate its spread”.

 

Action on AMR

The quantity of antibiotics used in livestock is vast and often includes medicines important for humans. Antimicrobial resistance is therefore seen as a threat to human health as well as animal health and food security. Farmers of poultry and pigs are particularly reliant on these treatments.

But usage of antibiotics for farm animals in Europe is falling. The latest report by the European surveillance of veterinary antimicrobial consumption showed sales down 34.6%. Overall, pigs, cattle, poultry and sheep along with goats accounted for 32%, 31%, 15% and 14%, respectively, of consumption. Average usage in the EU was 103.2mg/PCU[1].

[1] The Population Correction Unit or ‘PCU’ is a standardized measure of antibiotic usage that takes into account the weight of each animal at the time of treatment and also the total animal population.

 

Teagasc's pig development department carried out a research project in 2016 on 67 farms and found an average of 161mg/PCU. Ireland’s new national AMU-pig database, launched in November 2019 by the Department of Agriculture, Food and the Marine, has been gathering invaluable data on farm level antibiotic use in Irish pigs with farmers submitting information on a quarterly basis. The most recent figure is 119mg/PCU, which is a 26% reduction on 2016. The key is to use “as much as necessary but as little as possible”, explains Teagasc’s Carroll.8732553693?profile=RESIZE_400x

The UK pig sector’s target was to reduce antibiotic use by 64% by 2020 compared to 2015. The latest figure, at June 2020, showed 104mg/kg PCU, down from 278mg/kg PCU five years ago. The sector is “very, very close” to the 99mg target for 2020 says Veale: “There’s a really good story to tell.”

The impressive reductions made in the past few years are laudable but arguably the hard work starts now, admitted Professor S. Peter Borriello, Chief Executive Officer at the UK Veterinary Medicines Directorate in the most recent report by the Responsible Use of Medicines in Agriculture Alliance. Once the 2020 baseline is confirmed, the target is to reduce that by 30% come 2024. “… further reductions are likely to be harder to achieve and […] require a focus on preventing disease and improving farm management,” Borriello wrote.

Continued and sustained reduction in antimicrobial use on farms will require fundamental change in attitudes and behaviours. A safefood –funded study is underway to identify specific behavioural patterns and understand the factors shaping these behaviours, as well as potential resistance to change. The research, led by Teagasc, aims to identify a range of behavioural interventions to tackle the overuse or misuse of antimicrobials on farms on the island of Ireland.

 

Free from antibiotics? For those exporting pig meat products, like the UK and Republic of Ireland, the declines in antibiotic use offer strong marketing material. “Given our reliance on exports, and the progress being made in some of our competitor countries, it is vital that Ireland is able to both demonstrate and substantiate that progress is being made,” wrote David Graham, CEO of Animal Health Ireland, in a report for the antimicrobial and anthelmintic resistance conference, held in County Offaly in 2019.  However, there is nervousness around the term ‘antibiotic free’ meat. The perception then is that all other pork products contain antibiotics, explains NPA’s Veale, but there are safety measures in place, using strict withdrawal periods, to ensure consumers are not exposed to antibiotic residues.In 2016, British pork processor Karro registered an antibiotic-free logo with the Intellectual Property Office, and a year later launched products with a ‘raised without antibiotics’ label in supermarkets. Others have made similar moves though it remains niche. The Karro approach on farm is sound though, relying on individual treatment of animals. Farmers are much more clued into this kind of approach, but will be more keen to look at marketing their products as ‘antibiotic free’.

 

ABOUT Lucas Westphal


Lucas works as a Senior Bakery Scientist within the Baking and Cereal Processing Department at Campden BRI. He holds a BSc in home economics and nutritional sciences from the University of applied sciences Niederrhein in Germany and graduated with a first class in Food Science (MSc) from the University of Reading.

 

About Dan Hall

Dan has been with Campden BRI since 2011 and works in the Product Innovation team in the Food Manufacturing Technologies department. He has a degree in Chemistry and has written publications as part of Campden BRI’s member funded research programme.