̽��ֱ�� of Cambridge - livestock

Reducing the rise of antibiotic resistance

lw355 — Mon, 22 Nov 2021 12:00:01 +0000

Rising resistance to antibiotics is a worrying prospect, but a success story happening across the farms of the UK gives hope that something can be done.

Massive projected increase in use of antimicrobials in animals could lead to widespread antimicrobial resistance in humans

sc604 — Thu, 28 Sep 2017 18:00:00 +0000

̽��ֱ��researchers, from ETH Zürich, Princeton, and the ̽��ֱ�� of Cambridge, conducted the first global assessment of different intervention policies that could help limit the projected increase of antimicrobial use in food production. Their results, reported in the journal Science, represent an alarming revision from already pessimistic estimates made in 2010, pushed up mostly by recent reports of high antimicrobial use in animals in China.

In modern animal farming, large quantities of antimicrobials are used for disease prevention and for growth promotion. “Worldwide, animals receive almost triple the amount of antibiotics that people do, although much of this use is not medically necessary, and many new strains of antibiotic-resistant infections are now common in people after originating in our livestock,” said co-author Emma Glennon, a Gates Scholar and PhD student at Cambridge’s Department of Veterinary Medicine. “As global demand for meat grows and agriculture continues to transition from extensive farming and smallholdings to more intensive practices, the use of antimicrobials in food production will increasingly threaten the efficacy of these life-saving drugs.”

Global policies based on a user fee and stricter regulation could help mitigate those ominous projections. “Under a user fee policy, the billions of dollars raised in revenues could be invested in the development of new antimicrobial compounds, or put towards improving farm hygiene around the world to reduce the need for antibiotics, in particular in low- and middle-income countries,” said Dr Thomas Van Boeckel from ETH Zurich, the study’s first author.

Compared to a business as usual scenario, a global regulation putting a cap of 50 mg of antimicrobials per kilogram of animal per year in OECD countries could reduce global consumption by 60% without affecting livestock-related economic development in low-income countries.

However, such a policy may be challenging to enforce in resource-limited settings. An alternative solution could be to impose a user fee of 50% of the current price on veterinary antimicrobials: this could reduce global consumption by 31% and generate yearly revenues of between US$ 1.7 and 4.6 billion.

An important limiting factor in performing this global assessment was accessing sufficient data on veterinary antimicrobial sales volumes and prices. ̽��ֱ��present study is based on publicly available data, limited to 37 countries. Representatives from the animal health industry were approach for this study but all declined to share information on antimicrobial sales or prices.

̽��ֱ��research was funded by the program for Adaptation to a Changing Environment, the ETH postdoctoral fellowship program and the European Research Council.

Reference:
Thomas P. Van Boeckel et al. ‘Reducing global antimicrobial use in food animals.’ Science (2017). DOI: 10.1126/science.aao1495

Adapted from at ETH Zurich press release.

̽��ֱ��amount of antimicrobials given to animals destined for human consumption is expected to rise by a staggering 52% and reach 200,000 tonnes by 2030 unless policies are implemented to limit their use, according to new research.

Worldwide, animals receive almost triple the amount of antibiotics that people do.

Emma Glennon

Marcelo Braga

Expresso Porco

̽��ֱ��text in this work is licensed under a Creative Commons Attribution 4.0 International License. For image use please see separate credits above.

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Feeding food waste to pigs could save vast swathes of threatened forest and savannah

jeh98 — Thu, 10 Dec 2015 09:53:29 +0000

A new study shows that if the European Union lifted the pigswill ban imposed following 2001’s foot-and-mouth disease epidemic, and harnessed technologies developed in East Asian countries for ‘heat-treating’ our food waste to safely turn it into pig feed, around 1.8 million hectares of land could be saved from being stripped for grain and soybean-based pig feed production – including over quarter of a million hectares of Brazilian forest and savannah.

While swill-feeding was banned across the EU in 2002 following the foot-and-mouth outbreak – triggered by a UK farmer illegally feeding uncooked food waste to pigs – other countries, such as Japan, responded by creating a highly regulated system for safely recycling heat-treated food waste as animal feed.

Researchers describe the EU ban as a “knee-jerk reaction” that no longer makes sense when East Asian countries have demonstrated that food waste can be safely recycled. ̽��ֱ��models in the latest study show that pigswill reintroduction would not only decrease the amount of land the EU pork industry requires by 21.5%, but also cut in half the ever-increasing feed costs faced by European pig farmers.

Researchers describe swill as a feed which is commonly used in other parts of the world, one that could save a huge amount of global resources, and provide an environmentally sound recycling solution to the estimated 102.5 million tonnes of food wasted in the EU each year. Over 35% of food waste is now recycled into animal feed in Japan, where swill-fed “Eco-pork” is marketed as a premium product.

“Following the foot-and-mouth disease outbreak, different countries looked at the same situation, the same evidence, and came to opposite conclusions for policy,” said Erasmus zu Ermgassen from the ̽��ֱ�� of Cambridge’s Department of Zoology, who led the study, published today in the journal Food Policy. “In many countries in East Asia we have a working model for the safe use of food waste as pig feed. It is a highly regulated and closely monitored system that recycles food waste and produces low-cost pig feed with a low environmental impact.”

̽��ֱ��researchers examined data about the current land use of EU pork, the availability of food waste in the EU, and the quality and quantity of pork produced in feed trials that compared pigswill to grain-based diets, to produce a model of how much land could be saved if the pigswill ban was lifted.

Some 21.5 million tonnes of pork, around 34kg of pork per person, are produced in the EU each year. Livestock production occupies approximately 75% of agricultural land worldwide – with most of this used to produce animal feed. For EU pork, much of the environmental burden stems from the farming of soybean meal, which takes up in excess of 1.2 million hectares of land across South America.

As swill is much cheaper than grain and soybean-based pig feed, reintroducing swill feeding could reduce costs faced by EU pig farmers by 50%, say the researchers.

Most objection to swill feeding in the EU stems from concerns about safety, and the sentiment that feeding human food waste to pigs is unnatural. But zu Ermgassen argues that those concerns are largely based on incorrect assumptions.

“Pigs are omnivorous animals; in the wild they would eat anything they could forage for, from vegetable matter to other animal carcasses, and they have been fed food waste since they were domesticated by humans 10,000 years ago. Swill actually provides a more traditional diet for pigs than the grain-based feed currently used in modern EU systems,” said zu Ermgassen.

“A recent survey found that 25% of smallholder farmers in the UK admit to illegally feeding uncooked food waste to their pigs, so the fact is that the current ban is not particularly safe from a disease-outbreak perspective. Feeding uncooked food waste is dangerous because pigs can catch diseases from raw meat, but a system supporting the regulated use of heat-treated swill does not have the same risks,” he said.

With the demand for meat and dairy products forecast to increase 60% by 2050, reducing the environmental footprint of current systems of meat production will become increasingly critical.

zu Ermgassen points out that economic and environmental concern is driving a reassessment of EU animal feed bans that were put in place in the 2000s, as well as attempts to recycle food waste more effectively. ̽��ֱ��EU is currently looking into repealing bans on using waste pig and poultry products as fish feed and reintroducing insects as pig and poultry feed.

“ ̽��ֱ��reintroduction of swill feeding in the EU would require backing from pig producers, the public, and policy makers, but it has substantial potential to improve the environmental and economic sustainability of EU pork production. It is time to reassess whether the EU’s blanket ban on the use of food waste as feed is the right thing for the pig industry,” he said.

Erasmus zu Ermgassen’s research is funded by the Biotechnology and Biological Sciences Research Council.

Reference

Erasmus K.H.J. zu Ermgassen, et al. "Reducing the land use of EU pork production: where there’s swill, there’s a way" Food Policy Vol 58 (January 2016). DOI:10.1016/j.foodpol.2015.11.001.

Inset image: "Save Kitchen Waste to Feed the Pigs!" poster from the Imperial War Museums © IWM (Art.IWM PST 14743).

New research suggests that feeding our food waste, or swill, to pigs (currently banned under EU law) could save 1.8 million hectares of global agricultural land – an area roughly half the size of Switzerland, including hundreds of thousands of acres of South America’s biodiverse forests and savannahs – and provide a use for the 100 million tonnes of food wasted in the EU each year.

It is time to reassess whether the EU’s blanket ban on the use of food waste as feed is the right thing for the pig industry

Erasmus zu Ermgassen

Pigs eating swill at Stepney City Farm

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Field to fork: safeguarding livestock health

lw355 — Thu, 21 Jul 2011 09:45:03 +0000

About 17 billion chickens, almost 10 billion pigs, and nearly 2 billion each of cattle and sheep were produced as livestock worldwide in 2009. And, by 2050, demand for livestock is projected to double. With the added strain of increasing meat production on resources such as land, water, crops and energy, it’s vital to maximise the ‘output for input’, as Professor Duncan Maskell, Head of Cambridge’s Department of Veterinary Medicine and Marks and Spencer Professor of Farm Animal Health, Food Science and Food Safety, explained: “How you should apportion crops between food for animals and food and fuel for humans is a complex question, so it’s crucial to ensure that resource input counts in terms of output of meat, and one of the main moderators of this relationship is animal welfare, especially in terms of infectious disease.”

Viral epidemics can sweep through livestock, and endemic diseases such as respiratory infections can affect the rate at which animals grow. A further risk to food security is posed by bacterial infections of livestock that contaminate meat and cause food poisoning.

Research at the Department of Veterinary Medicine is tackling disease on all of these fronts in what Professor Maskell has described as “a perfect marriage between fundamental biological research and applied clinical outcomes.”

‘Flu-free’ chickens

A breakthrough was announced earlier this year that could prevent future bird flu outbreaks from spreading within poultry flocks. Dr Laurence Tiley, in collaboration with researchers in the Roslin Institute at the ̽��ֱ�� of Edinburgh, produced the world’s first genetically modified chickens that prevent the spread of avian influenza.

Since 2003, over 300 million poultry have been culled as a result of influenza outbreaks, and in some countries the virus is now endemic in wild bird populations. Preventing virus transmission in chickens would reduce both the economic impact of the disease and the risk for people who are exposed to the infected birds.

̽��ֱ��scientists introduced a new gene that manufactures a ‘decoy’ molecule into the chicken genome. In a clever move to confuse the flu virus into ignoring its own replication needs, the decoy mimics an important control element of the virus and diverts the viral replication machinery away from its own genetic material.

“Because the control element is absolutely conserved across strains, we expect that the decoy will work against all strains of avian influenza and be difficult for the virus to evolve around,” said Dr Tiley, whose research was funded by the Biotechnology and Biological Sciences Research Council (BBSRC). Although the birds become sick themselves, they don’t transmit the infection to other chickens, even those without the decoy molecule.

“At this stage, the chickens are not intended for consumption,” Dr Tiley added. “This genetic modification is a significant first step. Our objective now is to develop chickens that are completely resistant to avian flu.”

Threats from the wild

Viral epidemics are not just a concern in livestock, but also in relation to wildlife, as Professor James Wood explained: “Often, emerging infectious diseases originating from wildlife are a particular challenge because little might be known about the virus, how it’s transmitted to livestock and humans, or the potential for epidemics to spread.”

Nipah virus, for example, was first recognised in 1999 when an outbreak causing severe inflammation of the brain occurred in pigs and pig farmers in Malaysia. When the source of the virus was traced, it was found to be on fruit contaminated by infected fruit bats, the natural host of the virus.

“Bats epitomise the growing challenges associated with the spread of wildlife diseases,” added Professor Wood: “They are associated with a wide range of viruses, live in close proximity to animals and humans, and many important puzzles remain about the social, environmental and biological dynamics that shape pathogen transmission.”

̽��ֱ��first steps to remedy this lack of information were taken last year when a unique network was created comprising experts from institutions worldwide including collaborators in Bangladesh, Ghana and Kenya. ̽��ֱ��consortium was funded by a Catalyst grant from the Medical Research Council and three other research councils.

“ ̽��ֱ��network has a long-term aim of creating vitally needed interdisciplinary knowledge,” said Professor Wood, one of the leaders of the network, “as well as pioneering interventions geared to enabling bats, animals and people to co-exist with reduced disease risk.”

Super-vaccination at one sniff

Respiratory infections in pigs are a major animal welfare issue and cost the pig industry millions of pounds each year. An innovative project has begun the process of developing a ‘super-vaccine’ to guard against infection by the bacteria that are responsible for the most serious infections.

Funded with £5.6 million from the BBSRC, the consortium links experts from the ̽��ֱ�� of Cambridge, Imperial College London (the project co-ordinator), the London School of Hygiene and Tropical Medicine, and the Royal Veterinary College.

Dr Dan Tucker, who together with Professor Maskell leads the Cambridge component of the five-year project, explained why these infections matter so much to food security: “When a pig gets sick it diverts its energy away from growth to fighting off the infection. This requires treatment with antibiotics and decreases the efficiency with which vegetable protein is converted into kilograms of meat.”

̽��ֱ��goal is to create a single super-vaccine that can be administered by nasal spray and protect against Actinobacillus pleuropneumoniae, Haemophilus parasuis, Mycoplasma hyopneumonia/hyorhinis and Streptococcus suis. “Our gold standard would be to create a live vaccine based on a mutated version of one of these bacteria that no longer causes the disease, and then engineer it to display portions of the other three bacteria so that a strong immune response is made to all,” said Dr Tucker.

High-throughout sequencing in collaboration with the Wellcome Trust Sanger Institute is enabling the scientists to assemble the largest ever sequenced collection of these bacteria. ̽��ֱ��team has begun to identify which genes need to be ‘knocked out’ to provide a live vaccine – information that will also help in understanding why some strains cause more virulent disease than others.

Alongside vaccine development, a diagnostic kit will be developed to detect all four pathogens in less than six hours. ̽��ֱ��goal is to have a diagnostic test and potential vaccine ready for field trials at Huazhong Agricultural ̽��ֱ�� in China within three years.

Safety first

Diseases can also be spread by meat. Although the global incidence of food-borne illness is difficult to estimate, up to 30% of the population in industrialised countries may be affected each year according to the World Health Organization.

Salmonella and Campylobacter – two of the most common sources of food-borne disease – are the basis of multiple research programmes at the Department of Veterinary Medicine, such as the research led by Professor Maskell. His team has particularly focused on understanding the dynamics of the interactions of bacteria with their animal hosts.

“Thanks to the completion of genome sequences for many of the chief culprits and the advent of high-throughput sequencing,” said Professor Maskell, “the door has been opened on many of the secrets of how pathogens such as salmonellae cause disease.”

“We are committed to maintaining strong basic research, but do this in the context of finding improved intervention strategies,” he added. “Health standards and life expectancy have gone up globally, and a large part of this is better nutrition. At many levels this means more meat and high-protein food. One key aim of our research is to provide the fundamental knowledge and clinical tools to keep livestock healthy and our food safe.”

For more information, please contact Professor Duncan Maskell (djm47@cam.ac.uk) at the Department of Veterinary Medicine.

Veterinary research in Cambridge is spearheading a new generation of preventive methods to protect livestock from disease.

One key aim of our research is to provide the fundamental knowledge and clinical tools to keep livestock healthy and our food safe.

Professor Duncan Maskell

Norrie Russell, ̽��ֱ��Roslin Institute, ̽��ֱ�� of Edinburgh

Genetically modified chicken

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