Building Resilient Herds

Friday, September 25, 2026

A whole-farm strategy for today’s disease challenges

By Han Smits

Canadian pork producers operate in one of the most complex animal health environments the industry has ever seen. Diseases such as PRRS, influenza, PED, and emerging variants continue to evolve, spread, and challenge farms. Farmers are increasingly looking for solutions that go beyond reacting to each outbreak. They are asking a more fundamental question: How do we build herds that stay productive even when disease pressure rises?

Across the industry, the answer is shifting toward a broader concept: disease resilience. Rather than focusing only on preventing infection, resilience is about equipping pigs to maintain performance, recover quickly, and withstand the wide range of pathogens they encounter over their lifetime. It is a practical, long term strategy that strengthens the entire production system. No single tool — whether a vaccine, a feed additive, or a biosecurity protocol — can manage the full complexity of today’s disease environment. But when these tools work together, and when they are built on a strong biological foundation, the whole system becomes more stable, predictable, and profitable.

Why the disease challenge is changing

Historically, the swine industry saw a major new disease emerge roughly every decade. Today, the pace is much faster. Several forces are driving this trend: denser pig populations, more international movement of people, animals and feed, increased contact with wildlife, and climate driven expansion of disease carrying insects. Meanwhile, viruses such as PRRS mutate continuously, often outpacing animal immunity and existing vaccines.

For Canadian producers, this means that disease pressure is not only higher but also more unpredictable. Even farms with strong health programs can face setbacks when a new strain enters the region. This is why many veterinarians and researchers now emphasize the need for a system level approach — one that strengthens the pig itself, not just the tools around it.

Understanding resilience: more than avoiding infection

A key distinction is the difference between disease resistance and disease resilience. Resistance refers to the pig’s ability to prevent or limit infection. It is powerful when it works, but it is also narrow. Resistance is specific to a particular pathogen or even a particular pathogen strain, and its effectiveness can decline as that pathogen mutates.

Resilience, on the other hand, is broader and more durable. A resilient pig may still become infected, but it continues to eat, grow, and perform. Its immune system responds quickly and efficiently. It regulates inflammation without harming its own tissues. It maintains metabolic function under stress. And when a health event occurs, it recovers faster.

A resilient animal may carry a measurable pathogen burden, but the clinical and productive consequences are substantially reduced. For producers, this translates into fewer and shorter performance dips, more stable feed conversion, and less need for emergency treatments.

A whole farm system built on six pillars

Building resilience is not a single action. It is the result of multiple layers working together. There are six major pillars that form a comprehensive disease management system, each reinforcing the others.

The first is biosecurity, which remains the frontline defence. While no system is perfect, reducing the number of pathogens entering the barn lowers the burden on pigs and helps other health tools work more effectively. Good biosecurity protects vaccine investments and keeps pathogen pressure at manageable levels.

The second pillar is vaccination and veterinary protocols. Vaccines remain essential, but the most successful programs are those that adapt over time. Regular monitoring, diagnostic testing, and close collaboration with veterinarians help ensure that vaccination strategies match the strains circulating in the region.

The third pillar is nutrition and gut health. The gut is both a major immune organ and a major point of pathogen exposure. Diets that support gut integrity, maintain a balanced microbiome, and reduce unnecessary inflammation help pigs stay resilient under challenge. Consistency in feed quality and careful diet transitions also play a role.

The fourth pillar is environment and housing. Temperature swings, poor air quality, and overcrowding all weaken immune function. A stable, comfortable environment helps pigs maintain the physiological condition needed to withstand disease pressure.

The fifth pillar is surveillance and data. Early detection is one of the most powerful tools producers have. Tracking feed and water intake, monitoring mortality trends, and using diagnostics proactively allow farmers to respond quickly and limit the impact of health events.

The sixth pillar is genetics. Every other pillar interacts with the pig’s own biology and physiology. Biosecurity reduces exposure, but the pig still needs to respond. Vaccines trigger an immune reaction, but the strength and efficiency of that reaction vary between animals. Nutrition supports immunity, but pigs differ in how they use nutrients under stress. Genetics determines these differences.

Why genetics is becoming central to disease management

Genetic improvement for disease resilience is gaining attention because it offers something no other tool can: broad, permanent, cumulative progress. Once resilience traits are improved in breeding populations, those gains flow naturally into commercial herds across generations. Unlike pathogen specific resistance, resilience helps pigs cope with a wide range of diseases — including new or emerging ones.

Resilient herds respond more consistently to vaccines, tolerate unavoidable pathogen pressure more effectively, have less pathogen replication, shed less pathogens as a consequence and recover faster from health events. They also tend to require fewer antibiotic treatments, supporting responsible antimicrobial use and improving welfare outcomes.

Selecting for resilience is scientifically complex, because it involves many genes and requires data from pigs raised under real world conditions.

But the payoff is substantial: a herd that performs more predictably, even when disease pressure fluctuates.

A practical path forward for Canadian farms

Producers do not need specialized equipment or a particular feeding system to benefit from a resilience focused approach. The principles apply to all production phases, barns of all sizes and designs. By strengthening each pillar — biosecurity, vaccination, nutrition, environment, data, and genetics — farmers build a system that is far more robust than any single intervention.

In a world where disease pressure is rising, and new pathogens or different strains continue to emerge, resilience offers a practical, long term strategy for protecting herd health, improving welfare, and supporting the economic stability of Canadian pork production. BP