Liver abscesses may be costing Canadian beef producers far more than anyone realized a decade ago.
A Canadian beef quality audit conducted 10 years ago pegged the annual cost at $61 million. But that figure did not account for hidden losses like reduced growth efficiency, increased feed costs and added carcass trim. Modelled against more recent U.S. research (Taylor et al. 2025), the real number could be closer to $250 million.
“The important thing was that most of the losses that were associated with that number were before slaughter. So these are your increased energy maintenance,” said Rob Gruninger of Agriculture and Agri-Food Canada at the Alberta Beef Producers’ annual beef research showcase at the University of Lethbridge.
Read Also
First Canadian trial of Halter virtual fencing system underway near Westlock
The New Zealand-designed system uses GPS collars and is now eligible for OFCAF funding in Canada.
“A pen that has 20 per cent animals with liver abscesses will have four per cent increased maintenance energy cattle with A-plus liver.”
WHY IT MATTERS: With millions of dollars up for grabs in quality of cattle affected by liver abscesses, more proactive research and screening are critical in finding solutions other than antibiotics that may get banned by government eventually.
The per-animal loss ranges from $11 to $275, depending on severity. A-plus livers — severely abscessed with multiple small abscesses — carry the heaviest penalty, while A-minus livers with one or two small abscesses reduce carcass weight by roughly 29 pounds.
The detection problem
One of the biggest challenges is that liver abscesses are nearly invisible until slaughter. Cattle rarely show clinical signs unless severely impaired, and ultrasounds have proven ineffective at capturing the entire liver. Researchers hope a blood-based test using gene expression will soon fill that gap.
“If there was a way to identify it earlier, better (feed) management decisions would be great,” said Gruninger. “The closest thing I’ve seen in data related to that is the beef-on-dairy. Those animals are on feed for an extra 100 days relative to an Angus cow, and you see significantly higher rates of abscesses.”
What drives the condition
Industry estimates put incidence rates at 10 to 30 per cent across North America, with Canada on the higher end. Steers are more susceptible than heifers. More days on feed and more digestible diets both raise the risk. Dairy cattle have higher rates than beef cattle, with summer months worse than winter. Diets heavy on wheat and barley produce higher rates than corn or sorghum, and silage outpaces hay.
“The currently accepted theory of how liver abscess is developed is that it’s related to acidosis, and so the consumption of highly fermentable diets results in the rapid production of volatile fatty acids,” said Gruninger. “The rumen is only able to absorb those acids at a certain rate. So if you’re producing more acid than the animal is able to use for growth, then the pH of the rumen is going to decrease.”
When pH drops far enough for long enough, the rumen wall can be damaged, allowing gut bacteria into the bloodstream — a condition known as ruminitis. Those bacteria travel through the portal vein to the liver, where they can colonize and form infections. Emerging research also points to hind gut acidosis and epithelial damage in the cecum and colon as another possible entry point.
The core bacteria found in abscessed livers are Fusobacterium and Bacteroides. Both exist in healthy livers too, but at lower levels — meaning the triggering factors, including diet, stress and days on feed, are what tip the balance.
Growing pressure on antibiotics
Tylosin is the primary feed additive used to reduce liver abscesses, cutting incidence by 30 to 35 per cent without affecting gain. But federal pressure to reduce antimicrobial use in livestock is mounting, and Gruninger stressed the industry needs alternatives in case Tylosin is eventually banned.
Current approaches — more fibre and forage, yeast products, direct-fed microbials, essential oils and a dated fusobacterium-specific vaccine — have shown inconsistent or inconclusive results.
Gruninger recommended reducing chronic pen overcrowding, avoiding disruptions during diet transitions, choosing grains carefully and managing days on feed — all in combination with Tylosin until a better option emerges.
“I think the most feasible would be, ‘Could we figure out how to make a vaccine that works well enough that is cost effective and makes sense to use’?” he said. “Maybe targeting more than just fusobacteria.”
Why the cost is likely climbing
With beef cattle being pushed to greater finishing weights and more days on feed in recent years, the economic impact has almost certainly grown. Producers in the audience hypothesized the real cost may be five times the figures from a decade ago.
“The goal of the research is can we find some other (effective) ways,” said Gruninger.
