Pork labelling schemes ‘not helpful’ in making informed buying choices, say researchers
Researchers have evaluated different types of pig farming – including woodland, organic, free range, RSPCA assured, and Red Tractor certified, to assess each systems’ impact across four areas: land use (representing biodiversity loss), greenhouse gas emissions, antibiotics use and animal welfare. Their study concludes that none of the farm types performed consistently well across all four areas – a finding that has important implications for increasingly climate conscious consumers, as well as farmers themselves.
However, there were individual farms that did perform well in all domains, including an indoor Red Tractor farm, an outdoor bred, indoor finished RSPCA assured farm and fully outdoor woodland farm. “Outliers like these show that trade-offs are not inevitable,” said lead author Dr Harriet Bartlett, Research Associate at the University of Oxford's Smith School of Enterprise and the Environment, who was formerly at the University of Cambridge.
“Somewhat unexpectedly we found that a handful of farms perform far better than average across all four of our environmental and welfare measures,” added senior author Andrew Balmford, Professor of Conservation Science at the University of Cambridge. However, none of the current label or assurance schemes predicted which farms these would be.
“The way we classify farm types and label pork isn’t helpful for making informed decisions when it comes to buying more sustainable meat. Even more importantly, we aren’t rewarding and incentivising the best-performing farmers. Instead of focusing on farm types or practices, we need to focus on meaningful outcomes for people, the planet and the pigs – and assess, and reward farms based on these,” said Bartlett.
The findings also show that common assumptions around food labelling can be misplaced. For instance, Organic farming systems, which consumers might see as climate and environmentally friendly, have on average three times the CO2 output per kg of meat of more intensive Red Tractor or RSPCA assured systems and four times the land use. However, these same systems use on average almost 90% fewer antibiotic medicines, and result in improved animal welfare compared with production from Red tractor or RSPCA assured systems.
The way we classify livestock farms must be improved, Bartlett says, because livestock production is growing rapidly, especially pork production, which has quadrupled in the past 50 years and already accounts for 9% of greenhouse gas emissions from livestock. Pig farming also uses more antibiotics than any other livestock sector, and 8.5% of all arable land.
“Our findings show that mitigating the environmental impacts of livestock farming isn’t a case of saying which farm type is the best,” said Bartlett. “There is substantial scope for improvement within types, and our current means of classification is not identifying the best farms for the planet and animals overall. Instead, we need to identify farms that successfully limit their impacts across all areas of societal concern, and understand, promote and incentivise their practises.”
The study reached its conclusions using data from 74 UK and 17 Brazilian breed-to-finish systems, each made up of 1-3 farms and representing the annual production of over 1.2 million pigs. It is published today in the journal Nature Food.
“To the best of our knowledge, our dataset covers by far the largest and most diverse sample of pig production systems examined in any single study,” said Bartlett.
James Wood, Professor of Equine and Farm Animal Science at the University of Cambridge, commented: “This important study identifies a key need to clarify what different farm labels should indicate to consumers; there is a pressing need to extend this work into other farming sectors. It also clearly demonstrates the critical importance that individual farmers play in promoting best practice across all farming systems.”
Trade-offs in the externalities of pig production are not inevitable was authored by academics at the University of Oxford, University of Cambridge and the University of São Paulo.
The research was funded by the Biotechnology and Biological Sciences Research Council (BBSRC).
Reference: Bartlett, H.,‘Trade-offs in the externalities of pig production are not inevitable.’ Nature Food, April 2024. DOI: 10.1038/s43016-024-00921-2
Adapted from a press release by the University of Oxford.
Farmers don’t have to choose between lowering environmental impact and improving welfare for their pigs, a new study has found: it is possible to do both. But this is not reflected in the current food labelling schemes relied on by consumers.
The way we classify farm types and label pork isn’t helpful for making informed decisions when it comes to buying more sustainable meat.Harriet BartlettCharity Burggraaf/ GettyTwo pigs on a farm
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Fish fed to farmed salmon should be part of our diet, too, study suggests
Scientists found that farmed salmon production leads to an overall loss of essential dietary nutrients. They say that eating more wild ‘feed’ species directly could benefit our health while reducing aquaculture demand for finite marine resources.
Researchers analysed the flow of nutrients from the edible species of wild fish used as feed, to the farmed salmon they were fed to. They found a decrease in six out of nine nutrients in the salmon fillet – calcium, iodine, iron, omega-3, vitamin B12 and vitamin A, but increased levels of selenium and zinc.
Most wild ‘feed’ fish met dietary nutrient recommendations at smaller portion sizes than farmed Atlantic salmon, including omega-3 fatty acids which are known to reduce the risk of cardiovascular disease and stroke.
“What we’re seeing is that most species of wild fish used as feed have a similar or greater density and range of micronutrients than farmed salmon fillets,” said lead author, Dr David Willer, Zoology Department, University of Cambridge.
“Whilst still enjoying eating salmon and supporting sustainable growth in the sector, people should consider eating a greater and wider variety of wild fish species like sardines, mackerel and anchovies, to get more essential nutrients straight to their plate.”
In the UK, 71% of adults have insufficient vitamin D in winter, and teenage girls and women often have deficiencies of iodine, selenium and iron. Yet while, 24% of adults ate salmon weekly, only 5.4% ate mackerel, 1% anchovies and just 0.4% herring.
“Making a few small changes to our diet around the type of fish that we eat can go a long way to changing some of these deficiencies and increasing the health of both our population and planet,” said Willer.
The researchers found consuming one-third of current food-grade wild feed fish directly would be the most efficient way of maximising nutrients from the sea.
“Marine fisheries are important local and global food systems, but large catches are being diverted towards farm feeds. Prioritising nutritious seafood for people can help improve both diets and ocean sustainability,” said senior author Dr James Robinson, Lancaster University.
This approach could help address global nutrient deficiencies say the team of scientists from the University of Cambridge, Lancaster University, University of Stirling and the University of Aberdeen.
The study was published today in the journal, Nature Food.
The scientists calculated the balance of nutrients in edible portions of whole wild fish, used within pelleted salmon feed in Norway, compared to the farmed salmon fillets.
They focused on nine nutrients that are essential in human diets and concentrated in seafood – iodine, calcium, iron, vitamin B12, vitamin A, omega-3 (EPA + DHA), vitamin D, zinc and selenium.
The wild fish studied included Pacific and Peruvian anchoveta, and Atlantic herring, mackerel, sprat and blue whiting – which are all marketed and consumed as seafood.
They found that these six feed species contained a greater, or similar, concentration of nutrients as the farmed salmon fillets. Quantities of calcium were over five times higher in wild feed fish fillets than salmon fillets, iodine was four times higher, and iron, omega-3, vitamin B12, and vitamin A were over 1.5 times higher.
Wild feed species and salmon had comparable quantities of vitamin D.
Zinc and selenium were found to be higher in salmon than the wild feed species – the researchers say these extra quantities are due to other salmon feed ingredients and are a real mark of progress in the salmon sector.
“Farmed salmon is an excellent source of nutrition, and is one of the best converters of feed of any farmed animal, but for the industry to grow it needs to become better at retaining key nutrients that it is fed. This can be done through more strategic use of feed ingredients, including from fishery by-products and sustainably-sourced, industrial-grade fish such as sand eels”, said Dr Richard Newton of the Institute of Aquaculture, University of Stirling, whose team also included Professor Dave Little, Dr Wesley Malcorps and Björn Kok.
“It was interesting to see that we’re effectively wasting around 80% of the calcium and iodine from the feed fish – especially when we consider that women and teenage girls are often not getting enough of these nutrients”.
Willer said “These numbers have been underacknowledged by the aquaculture industry’s standard model of quoting Fish In Fish Out (FIFO) ratios rather than looking at nutrients.
The researchers would like to see a nutrient retention metric adopted by the fishing and aquaculture industries. They believe that if combined with the current FIFO ratio, the industry could become more efficient, and reduce the burden on fish stocks that also provide seafood. The team are building a standardised and robust vehicle for integrating the nutrient retention metric into industry practice.
“We’d like to see the industry expand but not at a cost to our oceans,” said Willer.
“We’d also like to see a greater variety of affordable, convenient and appealing products made of wild ‘feed’ fish and fish and salmon by-products for direct human consumption.”
The research was funded by the Scottish Government’s Rural and Environmental Science and Analytical Services Division (RESAS), a Royal Society University Research Fellowship, a Leverhulme Trust Early Career Fellowship a Henslow Fellowship at Murray Edwards College and the University of Cambridge.
Reference: D. Willer et al. Wild fish consumption can balance nutrient retention in farmed fish Nature Food DOI: 10.1038/s43016-024-00932-z
The public are being encouraged to eat more wild fish, such as mackerel, anchovies and herring, which are often used within farmed salmon feeds. These oily fish contain essential nutrients including calcium, B12 and omega-3 but some are lost from our diets when we just eat the salmon fillet.
Making a few small changes to our diet around the type of fish that we eat can go a long way to changing some of these deficiencies and increasing the health of both our population and planet Dr David Willer, Zoology DepartmentJoff Lee / The Image Bank / Getty Mackerel with potato salad
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Farm to factories
Cambridge Zero collaborates with Cambridge Global Food Security Interdisciplinary Research Centre (IRC) and the University of Cambridge Decarbonisation Network for two research events this month looking at industry decarbonisation and food security.
