Five things that Dr. John Campbell has learned about beef cattle health in 30 years

The annual event serves as the ideal hub for sharing knowledge about beef cattle health and management research and extension.

To kick off the day, Saskatchewan Agriculture Minister Daryl Harrison announced a $3.4-million investment from the federal and provincial governments in support of Integrated Genomics for Sustainable Animal Agriculture and Environmental Stewardship (IntegrOmes), a multi-year USask genomics research project.

The field day’s keynote speaker was Dr. John Campbell (DVM), a well-known beef cattle specialist at the Western College of Veterinary Medicine (WCVM). He shared five key insights gained through his work as a teacher, researcher, clinician and the co-leader for two cow-calf surveillance networks — initially in Western Canada and then across the country.

Campbell has also served as the longtime director of the WCVM’s Disease Investigation Unit (DIU). This unit is a partnership between the WCVM and the Saskatchewan Ministry of Agriculture that has operated as a vital disease surveillance tool in the province for nearly three decades.

“Since 2007 we've (the DIU) had really consistent funding from Saskatchewan [Ministry of] Agriculture, which is wonderful,” said Campbell.

He added that all the DIU’s 300-plus investigations took place across Saskatchewan, each conducted in partnership with local veterinarians and livestock producers.

Campbell, who has been a veterinarian for four decades and a member of the college’s faculty for 33 years, retired from the WCVM at the end of June.

Beef cow-calf producers have mostly embraced vaccination programs for their cows and calves, and data collected through the cow-calf surveillance network indicates that most producers are using the core vaccines. The Beef Cattle Research Council recommends that all cow-calf producers vaccinate their herd against bovine viral diarrhea virus, bovine herpesvirus type 1, bovine respiratory syncytial virus and clostridial bacteria.  

Campbell suggested that disease outbreaks caused by failure to vaccinate appropriately are much less common now than they were when he first started as a clinician. He shared a historical example of one cow-calf herd in northeastern Saskatchewan that lost many calves due to the herd missing about $300 worth of vaccines.

Infertility in cattle is still difficult to diagnose. One of the major reasons is the low number of diagnostic lab submissions of aborted fetuses and the cost attached to these kinds of disease investigations.

Campbell said he continues to see outbreaks of infertility in cattle, with cows aborting or not being able to get pregnant in the first place. He explained that these issues can be caused by a range of factors with some problems starting roughly four to five months before a producer notices any signs.

Campbell said the issues may originate in the breeding season or are linked to nutritional deficiencies before the season begins: “Maybe the trace minerals (levels) are okay now, but they were deficient a while ago.”

“This is just a partial list of some of the diseases that have emerged since I graduated from vet school,” said Campbell, a 1985 graduate of the Ontario Veterinary College. The list he shared with the audience included:

• bovine spongiform encephalopathy (BSE)
• Salmonella dublin
• Mycoplasma bovis
• highly pathogenic avian influenza in U.S. dairy cattle
• digital dermatitis
• toe tip necrosis syndrome

In the 1990s, Campbell recalled receiving phone calls from producers reporting that “antibiotics aren't working.” These cases often involved cows with chronic pneumonia and arthritis, and sometimes it was in cow-calf herds. After those first cases, Mycoplasma bovis became one of the dominant diseases in beef cattle for multiple years.

In dairy cows, one of the common conditions he saw in Western Canada was digital dermatitis, also known as strawberry foot rot or hairy heel wart. This disease has now become more common in feedlots and even in cow-calf herds where treatment options are far more challenging.

“Almost 50 per cent of the disease investigations that we deal with are either nutritional or toxic,” Campbell said. “That's why so much of the cool work you see going on here at the LFCE and at the University of Saskatchewan is to do with nutrition.”

In Western Canada, one common issue that affects beef cattle is a deficiency of copper, a trace mineral that’s essential for reproduction.

“They're [cattle] not very good at regulating the copper in their blood, so it's absorbed and stored … primarily in the liver,” said Campbell. “It's actually a pretty small margin between having adequate copper and having too much copper. It’s important to recognize that we can also overdo copper supplementation and create toxicity.”

Campbell advised that feed testing is very important, but it’s difficult to sort out trace mineral requirements on paper due to all the interactions. Having a sample of cattle tested for trace minerals by blood sampling or through a liver biopsy is a valuable tool in evaluating trace mineral status.

“The last lesson I learned — and this is probably the hardest one — is that there are still lots of unknowns out there,” said Campbell.

In the past decade, Campbell said he has seen health issues in about six to seven herds that have baffled him. The most recent one involved a herd where many of the calves’ birth weights were between 30 and 50 pounds below average. The tiny calves could still walk under their mothers’ bellies at three weeks old.

The farm had a large cow-calf herd with 2,000 heifers calving and a breeding program including 25 different bulls.

“They had probably 40 to 60 per cent of their calves [affected],” said Campbell. “If anything, else went wrong, if there was a storm… those calves would die just because they were so tiny. And I’m still not sure what caused this.”  

As the veteran scientist summed up his work, about a dozen USask students were listening intently from the sidelines. These graduate students spent the day presenting their livestock- and forage-focused research posters to LFCE visitors — demonstrating that the search for solutions is continuing with the next generation of researchers.