British hog farmers reduce carbon footprint

A recent study found producers cut their impact on the environment by 40 percent through changes to genetics and feed

Genetic and feed changes have reduced the carbon footprint of British pig farming by nearly 40 percent during the last two decades, reports a recent study.

Canadian pig farming would likely show similar results, although on a smaller scale, said Ilias Kyriazakis, a professor at the Institute for Global Food Security at Queen’s University Belfast’s School of Biological Sciences in Northern Ireland.

“The conclusions of our study were quite surprising, actually, because we didn’t expect such dramatic effects.”

The British study was led by Kyriazakis and funded by the European Union. It was sparked by increasing global concern over the contribution of the livestock industry to climate change.

The United Kingdom has set an emissions target of carbon neutrality for farming by 2050.

The positive message from the study is British pig producers reduced their carbon footprint between the years 2000 and 2020 “without having the main aim to reduce environmental impact,” he said.

The reduction came about independent of environmental motivations, due to changes in pig genetics, said Kyriazakis. They include an increase in growth rates, with pigs becoming leaner and more efficient at converting their food, reducing the carbon footprint by an estimated 20 percent.

It was also due to changes in what British pigs are fed, he said. They were originally given things such as soybeans, most of which were imported to the U.K. from countries such as Argentina and Brazil.

Not only was the feed transported thousands of kilometres, almost half of it came from newly deforested land, “so the carbon footprint is really very high,” said Kyriazakis. It accounted for an estimated 75 to 80 percent of the carbon footprint of British pig farms.

There has been a push in Europe during the last 10 years to instead use homegrown feed containing things such as canola and sunflower meal, he said.

This trend has joined advances in feed technology ranging from synthetic amino acids to enzymes, “which enhance the adjustability of minerals like phosphorus, so all these things have contributed to a reduction in the environmental impact of the pig systems.”

Such feed supplements, when added to domestic feedstuffs such as canola, “reduced nutrient excretion in manure, while boosting animal productivity by as much as 30 percent,” said a statement by Queen’s University Belfast.

The study also estimates the supplements helped lower phosphorus levels in runoff from pig manure by more than 20 percent. Pig farming is considered to be a major contributor to eutrophication in bodies of water, resulting in excessive growth of aquatic plants that can kill fish due to lack of oxygen.

Pig production is responsible for about 10 percent of the carbon footprint of the British livestock industry.

“Although the environmental impact contribution per unit of meat from pig systems is relatively low, pig meat is the meat type most produced and consumed globally,” said the university statement.

As a former adjunct professor at the University of Guelph in Ontario, Kyriazakis expected similar genetics likely also resulted in cuts to the carbon footprint of Canadian pig farmers. However, the overall reduction will probably be smaller than in the U.K. because sources for feed are grown locally rather than imported, he said.

The study was recently published in the scientific journal Agricultural Systems. It is based on public databases in England, Scotland and Wales for the years 2000 to 2020, said the statement by Queen’s University Belfast.

“Because the data on agricultural inputs was sparse, a new research methodology was developed in which outputs were used to retrospectively estimate inputs — a process called ‘inverted modelling’.”

By calculating the effect of pig farming in the past, it becomes possible to develop better approaches to reduce greenhouse gases and other environmental problems in the future, said Kyriazakis. They include the use of new technologies such as precision feeding that enable farmers to better match the composition of feed to the needs of pigs, he said.

The study potentially has lessons for all livestock producers, not just pig farmers, he said in the university statement.

In an interview, he said farmers can no longer ignore increasing public concerns about climate change.

“The question is whether then a consumer would be prepared to accept that moving towards production of meat with a zero-carbon footprint might be more expensive, for example, and whether they would be willing to pay.”

A Canadian coalition called Farmers for Climate Solutions recently asked the federal government for $300 million to establish six national programs to reduce agricultural greenhouse gas emissions.

When asked if Canadian farmers could find themselves at a competitive disadvantage if producers in markets such as Europe manage to achieve carbon neutrality ahead of them, Kyriazakis said “that’s a very good question.”

One possibility is that foreign governments could start applying an environmental tax on agricultural imports that don’t meet their standards, he said, noting that Canada exports products such as bacon to the U.K.

“But these are questions for the policymakers, not for me.”

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