Beyond the nose: boar taint quick-test moves into validation testing
By Lilian Schaer, Livestock Research Innovation Corporation for Ontario Hog Farmer, October/November 2020
New research is underway to bring a quick test for boar taint one step closer to commercialization.
Male piglets are castrated to ensure pork doesn’t give off an unpleasant odour when it is cooked. That smell, known as boar taint, is caused by two compounds, skatole and androstenone, which are produced by intact male pigs.
Castration is stressful for the animals and labour-intensive for farmers, so the search has long been on to identify the genetic markers in pigs that cause boar taint - led by the University of Guelph’s Prof. Jim Squires - in hopes of breeding animals with reduced levels of the compounds in question.
Currently, the gold standard for detecting boar taint in intact hog carcasses at slaughter is the human nose test, which involves trained people smelling meat, an expensive and time consuming process.
Enter Prof. Maria DeRosa, Chair of the Chemistry Department at Carleton University. She has developed a tool similar to a home pregnancy test that can rapidly detect the presence of the two compounds. The small test strip changes colour if the compounds are found, giving results quickly without needing to send samples to a lab.
Her biosensor uses aptamers – small, single-stranded nucleic acids that can bind to large or small target molecules - that she and her research team have identified as capable of binding to skatole and androstenone.
A subsequent research partnership with the Canadian Centre for Swine Improvement (CCSI) helped DeRosa test the effectiveness of her test strip compared to human sniffers in a small-scale trial that was part of a larger project involving human nose trials.
“We found that the human nose correctly identified the compounds 10 out of 15 times, and our strip was able to achieve 14 out of 15 times,” says DeRosa. “We were very excited to learn that against the gold standard, we can outperform with test strips.”
This has brought DeRosa and CCSI to the latest project that is now underway, a phase one validation of the tool in a setting outside a laboratory. If that goes well, further validation will take place on the processing line of a commercial slaughter plant to test the tool’s speed and accuracy in a real-world setting.
The goal, according to DeRosa, is an accurate test that is consistently reproduceable and can be used by anyone.
“If we can’t make enough tests and they’re not reproduceable or we have results that aren’t accurate, then we need to go back to the drawing board to improve the test,” she says. “We need to confirm the technology is sound before moving on to the next step.”
Even if DeRosa’s test is only as good as the human nose, it will still be faster and more economical - key for the industry to move ahead with any kind of widespread approach to raise male pigs without castration, notes CCSI CEO Brian Sullivan.
“Boar taint itself currently isn’t a big issue because castration is standard practice, but not having to castrate young males means better animal welfare and faster-growing, more efficient and leaner carcasses - there are a lot of positives about it,” Sullivan says. “If it’s practical and economical enough, it could become a routine quality control (at processing).”
The current research phase includes the completion of testing on approximately 200 samples. CCSI has already completed human nose and lab tests for those samples.
Aptamer technology is already used in other fields, so DeRosa does not anticipate regulatory challenges preventing the tool from coming to market if it is successful.
Funding for the phase one validation project is provided by Ontario Pork; a funding application for phase one has also been submitted to Mitacs, a Canadian not-for-profit organization that supports research and innovation.
This article is provided by Livestock Research Innovation Corporation as part of LRIC’s ongoing efforts to report on Canadian livestock research developments and outcomes.