Imagine a world where bird flu, a seemingly distant threat, suddenly becomes a reality for dairy farmers. This is the story of H5 avian influenza, a global challenge that has left its mark on US dairy cattle and serves as a wake-up call for Australian farmers.
The year 2024 marked the beginning of a journey that would change the way we view animal health. H5 bird flu, an unwelcome visitor, made its presence known in US dairy herds, causing a ripple effect of illness and production losses. But here's where it gets controversial: the virus didn't just affect the birds; it jumped into dairy cows, a move that was unprecedented and eye-opening.
Australia, thankfully, has remained free from this particular strain, but the experience across the Pacific offers valuable lessons. The Federal Government, in collaboration with states, territories, and industry, has taken proactive steps to enhance national preparedness. From improved surveillance to better coordination across animal, wildlife, and human health agencies, they've left no stone unturned.
Dairy Australia, supported by the Department of Agriculture, Fisheries and Forestry, commissioned an independent risk assessment to understand the potential impact of H5 bird flu on Australian farms. The findings, shared through a recent webinar, provided a clear roadmap for farmers to navigate this potential threat.
The assessment revealed a low risk of H5 bird flu entering the Australian dairy herd, and even if it did, the spread between farms was expected to be minimal. This lower risk is attributed to various factors, including lower farm density and fewer routine cattle movements. Australia's advantage lies in being pre-warned, unlike the US, where the outbreak took everyone by surprise, resulting in a period of uncontrolled spread.
If H5 bird flu were to arrive in Australia via bird migration, dairy farmers would need to be vigilant for specific clinical signs. The most consistent signs observed in infected US herds included a sudden drop in milk production, abnormal milk resembling severe mastitis, fever, and lethargy in cows. While mortality rates were low, the morbidity was high, with many cows taking weeks or even months to recover their production levels.
So, what can Australian dairy farmers do to prevent the introduction and spread of H5 bird flu? The US outbreak has provided some simple yet effective measures.
For animal movements, quarantine and observation before cows join the milking herd can reduce exposure. Testing protocols for cattle movements and bulk-milk screening have also been implemented in the US.
Maintaining milking hygiene is critical. Milking affected or suspect cows last or separately, where possible, can limit the spread via liners and cups. Careful handling of mastitic milk, thorough equipment cleaning, and consistent teat preparation are all essential practices.
Reducing milk aerosols, or airborne milk droplets, is another practical step. High-pressure hosing of milk spills can create fine aerosols, so using lower-pressure wash-down methods and minimizing splash helps reduce exposure.
Protecting the people on the farm is also crucial. Wearing gloves during milking and when handling milk or sick animals, washing hands after glove removal, and managing contaminated work clothing are all practical biosecurity measures. Encouraging seasonal flu vaccination further reduces the risk of dual infection.
Surveillance is key, and it relies on farmers' instincts. Unusual clusters of mastitis-like illness, sudden production drops, or unexplained bird deaths should prompt early advice and action.
In the end, preparedness comes down to the fundamentals. A well-written and up-to-date biosecurity plan is the foundation of a resilient dairy farm.
So, what do you think? Are these measures enough to keep H5 bird flu at bay? Share your thoughts and experiences in the comments below.
- Andy Hancock, Dairy Australia
