The celebration of clinical veterinarian Dr Merlyn Hay's discovery of Mycoplasma bovis in an outbreak of unusual mastitis and lameness in a South Canterbury dairy herd, led to her recognition as an Outstanding Contribution to the Primary Industries Award. This has potentially saved the country millions of dollars and may enable a world first eradication.

It reminds us the role clinical veterinarians, farm managers, owners, universities, laboratories, government and industry organisations have in protecting our biosecurity.

From a veterinary perspective, the clinical veterinarian is an important 'foot soldier' in being 'on-farm' to act as a sentinel to help the farmer detect early disease or an incursion in biosecurity. Never be afraid to involve your veterinarian if you are unsure. Or otherwise a government helpline to report exotic pests and diseases you can call the hotline 24/7 to report suspected pests or diseases that should not be in New Zealand. This includes land, freshwater and marine pests or diseases in plants and animals.

Vigilance in the early detection and monitoring of disease by farm managers and owners is a key plank in the armoury of protecting our agricultural industry.


Biosecurity on the other hand is a vital part in minimising the introduction or spread of potential disease. Whilst most farmers are unknowingly or knowingly providing security measures, there is a lot more that can be done now that the authorities reflect on the Mycoplasma outbreak.

Animal movements, whether motivated or not, was the movement of early calving cows or cows that had slipped a calf but came into milk. These were often transported to a dairy platform or neighbour who was prepared to milk it. These cows are best kept on farm, either being milked or dried off and culled at the works. They are best kept isolated from the remainder of the herd. This also happens if a shed is not operational in early spring.
At the autumn end of the season, winter grazing, or more importantly the return of the herd with some 'extra' foreign cows inadvertently present. The same applies with 'break-ins' or 'break-outs' of calves with the neighbours.

Calf rearing facilities with multiple sources provides an opportunity for mix and transmission of disease. The feeding of raw milk or untreated milk is well documented — but the purchase of whole milk/colostrum from sources that is a premium (herd vaccinated for Rotavirus) or free (antibiotic contaminated) can be a Trojan horse.

The tagging of stock at source with issued NAIT tags activated on the register has been well publicised. Farmers are being reminded of this as we approach spring calving.

Farm biosecurity isn't a few well-intentioned signs swinging on the gate entrance, an empty footbath and sprayer. Farmers, it seems in outbreak regions have been observed to become apathetic after a few months. It is something we all need to work harder at and reinforce the vigilant behaviour to all.

After all, it seems every few years at an accelerating rate we are detecting newer biosecurity threats — Salmonella Brandenburg, Theileria and Mycoplasma to name just a few.