OPINION: Winter is almost behind us with the days getting longer and warmer. Calving and lambing are now under way with ground conditions firming up after a very wet May, June.

For me as a cattle finisher, the next five months are critical because I do a high percentage of buying and selling for the year.

But this time around, farmers have new challenges with the Mycoplasma bovis factor coming into play. How do they minimise the risk without compromising production and profit?

As a trader-finisher, most of my bulls stay on farm for only 12 months on average and, once on farm, they never mix with other mobs. This has always been the case as mixing bulls often leads to social misconduct, which can often lead to some poor bull being abused.

The biggest risk to my operation is if I was to become one of the very unfortunate farmers who has brought on to their property an infected animal. The MPI restrictions that apply if a property is put under Notice of Direction could be worse than the disease itself.

Another problem is the number of calf rearers who have chosen not to rear calves this year. This will have a flow-on effect for many years and I expect the 100kg calf market will be extremely buoyant. I have had 100kg calves quoted this week for $640.

I've had people ask me why we need to carry on with this cow culling. The answer is simple: we have one chance of eradicating this cruel disease from our shores and I am sure the next generation will thank us if we are successful.

Others have pointed out "other countries such as Australia have learned to live with Mycoplasma, so why can't we"?

The fact is we don't have the same strain as our neighbours; ours is more virile and is likely to cost the dairy industry 10per cent of the national herd each year. Because this disease is very hard to test reliably for, the job of eradication is not at all assured but if successful it is likely to take many years to achieve. I take heart at what great progress the TB eradication team have made over recent years and I hope science will come to the rescue to our latest incursion.

For those who argue that we should not have pursued eradication but instead have opted for the 'managed control' pathway, keep this in mind. With eradication, there is compensation for farmers with infected animals. If we have to move to managing the disease, compensation to farmers affected will be zilch. For helpful advice on M. bovis, Beef & Lamb and Dairy NZ have a lot to offer and check out the MPI website.