Layered Plan Needed To Fight BVD

In fact, a recent New Zealand survey of farmers and veterinarians found that while awareness of BVD is generally high, many farmers rely on a single control measure rather than the more comprehensive approach recommended by veterinarians.

The challenge is that BVD often goes unnoticed until it starts affecting reproductive performance, calf health or growth rates. By then, the virus may already be well established within the herd.

The most significant losses occur in breeding herds. When pregnant cows are exposed to BVD during a critical stage of gestation, the result can be empty cows, abortions, weak calves or the birth of persistently infected (PI) animals.

These PI animals are central to the ongoing spread of BVD. They are born carrying the virus and shed it continuously throughout their lives, exposing other cattle wherever they go.

From a beef farming perspective, this is particularly important because PI animals can move through trading, grazing and breeding systems while appearing outwardly normal.

A PI calf in a mob may be responsible for infecting numerous other animals before anyone realises there is a problem.

BVD can also impact growth rates and overall animal performance. Animals exposed to the virus may experience immune suppression, making them more susceptible to other diseases and reducing productivity.

One of the key findings from last year’s survey was that many farmers approach BVD using a single control method. Some rely primarily on vaccination. Others focus on testing. Some place most of their emphasis on biosecurity.

Veterinarians consistently recommended an integrated approach.

Rather than relying on one strategy, vets advocated for a layered programme that combines testing, biosecurity, vaccination and ongoing monitoring.

This approach recognises that each farm has different risk factors.

For example, purchasing breeding stock, introducing bulls, trading cattle, sharing boundaries with neighbouring properties and grazing animals off-farm can all create opportunities for BVD to enter a herd.

Understanding these risks is a critical first step.

Producers should work with their veterinarian to establish their herd’s current BVD status and identify where exposures may occur. Testing programmes can help identify infection and detect PI animals, while biosecurity measures can reduce the likelihood of introducing the virus in the future.

Protecting breeding animals is another key priority. Vaccination can be an important part of a wider herd health programme, helping reduce the risk of fetal infection and the creation of future PI animals.

However, vaccination should not be viewed as a standalone solution.

The farms achieving the strongest outcomes are typically those that take a broader approach and regularly review their BVD management plan.

To support those conversations, a practical BVD decision guide has been developed to help farmers assess their current level of risk and identify opportunities for improvement.

The guide focuses on four key questions:

• Is your herd genuinely closed?
• Do you know your herd’s BVD status?
• Are breeding animals protected?
• Is your BVD control plan complete?

Depending on the answers, the guide outlines practical next steps, including monitoring, testing, PI detection, biosecurity improvements and vaccination.

The recent survey reinforces a simple but important message. BVD control is not a one-off decision or a single farm practice. It requires a coordinated approach that reduces risk from multiple angles.

For beef farmers, that means looking beyond individual management tools and considering how the different pieces fit together.

By working with your veterinarian and adopting a comprehensive strategy, you can reduce the impact of BVD on reproductive performance, calf health and long-term herd productivity.

• Andrew MacPherson is veterinary technical advisor, MSD Animal Health