No cattle breed is completely immune, but susceptibility varies significantly depending on the breed, age, management, and exposure history. Here’s what we know about which cattle breeds tend to be most affected and why dairy (milk) cows often appear more vulnerable, while well-bred animals sometimes show better resistance.
Breeds Most Attractive / Susceptible to FMD
There is no single “most attractive” breed in the sense that one is uniquely targeted by the virus. However, certain breeds and types consistently show higher reported infection rates and more severe clinical signs in outbreaks worldwide (including South Africa):Dairy breeds (especially Holstein-Friesland, Jersey, Ayrshire, and their crosses)
These are the breeds most frequently and severely affected in South African outbreaks. In recent KZN, Free State, and Eastern Cape data, Holstein-Friesland and Jersey cows dominate the reported cases.
Why dairy cows are more vulnerable / “attractive” to FMD:
High metabolic stress — Lactating dairy cows are under intense physiological stress (producing 30–50+ litres of milk per day), which suppresses their immune response and makes them more susceptible to infection and severe clinical disease.
Close confinement and high stocking density — Dairy cows are usually kept in milking parlours, feedlots, or high-density barns with frequent close contact, facilitating rapid virus spread.
Frequent human handling — Daily milking, movement to and from parlours, and shared equipment increase transmission risk (the virus spreads via saliva, milk, faeces, and aerosols).
Young calves and heifers — Dairy herds often have a high proportion of young, immunologically naïve animals, which show more dramatic clinical signs (mouth and foot lesions, lameness, drop in milk yield).
Milk as a transmission route — The virus is shed in milk, which can spread it mechanically during milking or if milk is fed to calves.
In contrast, extensive beef herds (especially Nguni and other indigenous breeds) often show milder clinical signs and lower mortality, partly due to lower stocking density, less stress, and more natural immunity from prior low-level exposure.
Good Breeding / Well-Bred Animals and Resistance
Well-bred, high-genetic-merit cattle (especially in commercial dairy and beef operations) do not have true genetic resistance to FMD — the virus can infect any cloven-hoofed animal — but they often show better outcomes for several reasons:
Stronger overall health and immunity — Animals with good genetics tend to have better body condition, stronger innate and adaptive immune responses, and recover faster from infection.
Better nutrition and management — High-merit animals are usually on balanced, high-quality feed programmes, which support a stronger immune system and reduce the severity of clinical signs.
Lower mortality and faster recovery — Well-managed, well-bred herds often experience lower death rates and quicker return to production (especially milk yield) compared to poorly managed or indigenous herds under stress.
Selective breeding indirectly helps — Traits like good feet/conformation (less lameness), strong udder health, and high feed efficiency can reduce secondary complications during FMD outbreaks.
However, no amount of “good breeding” makes cattle resistant to infection. The virus infects via the respiratory tract, mouth, or skin abrasions, and clinical disease severity depends more on viral dose, strain, age, stress level, and concurrent health issues than on breed genetics.
FMD is caused by a highly contagious virus (aphthovirus) that infects any cloven-hoofed animal. No naturally occurring breed of cattle is genetically immune or resistant to infection. All breeds — Holstein, Jersey, Angus, Nguni, Brahman, etc. — can become infected when exposed to sufficient viral load.
Well-bred, healthy cattle usually suffer much milder disease and recover much faster than stressed, poorly fed, or genetically average animals. The key mechanisms are:Stronger innate and adaptive immune response → faster clearance of the virus.
Better body condition score (BCS) → more energy reserves to fight infection and repair tissue.
Lower physiological stress → less suppression of immunity (lactating dairy cows are hit hardest because of metabolic stress).
Superior hoof and mouth tissue integrity → fewer severe lesions, less secondary bacterial infection, less lameness, and quicker return to eating/milking.
Higher colostrum quality in calves from well-bred dams → better early-life passive immunity.
Real-world observations (including South African outbreaks):
High-genetic-merit Holstein and Jersey herds in well-managed dairies often show high infection rates but lower mortality and faster return to full milk production than poorly managed or indigenous herds under stress.
Nguni and other indigenous breeds in extensive systems frequently show very mild or subclinical infections (sometimes only detected serologically), partly because of lower stress and historical low-level exposure building herd immunity.
Feed quality is one of the biggest leversPoor nutrition dramatically worsens FMD outcomes. High-quality feed helps in these ways:Balanced protein, energy, minerals (especially zinc, selenium, vitamin E) → stronger immune function.
Adequate fibre and rumen health → better overall resilience.
Reduced metabolic stress in high-producing animals → less immunosuppression.
Studies and field experience show that cattle in good body condition with balanced rations:Develop fewer and less severe lesions.
Shed less virus (lower transmission).
Recover appetite and production faster.
Have lower case-fatality rates (especially in calves).P
Practical impact
Better breeding + excellent feed quality + low-stress management =
→ Higher resistance to severe disease
→ Lower mortality
→ Faster recovery
→ Less economic loss per animal
But:
→ Still get infected if exposed to enough virus
→ Still transmit the virus to others
→ Still lose export status if infected
→ Still need vaccination + biosecurity as the primary control tools
In South Africa’s current crisis, the single biggest levers remain:Mass vaccination coverage (the only realistic way to stop spread) Strict movement control and biosecurity -Early detection and culling/quarantine when required
Better genetics and feed make the disease less devastating when it hits, but they do not stop it from spreading or protect trade status. That’s why experienced farmers keep repeating: “Vaccinate hard, vaccinate fast, and lock down movement — everything else is secondary.”
Dairy breeds (Holstein-Friesland, Jersey, etc.) appear “most attractive” to FMD because of high stress from lactation, close confinement, frequent handling, and large numbers of young animals — not because the virus prefers them genetically. Well-bred animals often cope better due to superior health, nutrition, and management, but they are not resistant. The best defence remains vaccination, strict biosecurity, movement controls, and rapid reporting — regardless of breed.
In South Africa’s current outbreak, the focus should stay on universal vaccination coverage and breaking transmission cycles rather than hoping genetics alone will solve the problem.
More than 250 breeds of cattle exist globally. But which of those perform the best and yield a stronger return on investment for producers? A cow’s breed will have a big impact on its size, weight, reproductive efficiency, and more. Breed types will also affect how much feed an animal needs, which can shift production costs and your bottom line. There are over 70 established cattle breeds in the United States, accounting for more than 28 million beef cows as of the beginning of 2024. Here’s a look at some of the top cattle breeds that U.S. ranchers can consistently rely on.
