Check ram team to ensure it is sound

01-02-2010 | Trevor Cook

Luckily disastrous animal health events are rare.

I have always commented on the fact that most of the income losses due to animal health events occur without any obvious signs. Reduced liveweight gains due to worms or trace-element deficiencies are the big ones because the loss occurs every day and in most of the animals in a mob. A 0.2kg/day drop in the weight gain in a mob of 100 yearling steers due to low copper over that magical 100 days of spring is 2000kg of lost body weight. This will occur without any outward sign at all.

These are real outcomes that I have monitored. So a roughly $4000-loss could have been prevented by a $700 late winter treatment. Of course if copper is not low then the $700 is truly a cost, so some monitoring history helps the odds of a return on that cost.

Animal health events that result in lots of dead or dying animals are always dramatic and can also add up to substantial costs. Often, but not always, there are ongoing production costs over and above the lost animals. Such events are often the result of a major mistake. Overdosing with trace elements is the most common, and in particular selenium. I have seen two situations in which there were huge losses of lambs due to miscalculation of the dose being administered. In such cases it is not a matter of doubling the dose. It is the result of animals getting nearer 10 times or more of the correct dose. There is really no excuse for these losses.

Losses that occur after "routine" actions are more common. One that crops up endlessly is the consumption of toxic plants. Seeing a large valley basin littered with dead breeding cows that had consumed Tutu remains embedded in my mind. As do the dead and dying Friesian bulls that had a few weeks before cleaned up the wilted remains of a farm-wide ragwort crop that had been sprayed. Smaller losses due to consuming Ngaio, Rhododendron or Oleander seem always to be occurring, particularly on lifestyle blocks.

Those Taihape ewe deaths way back associated with DAP applications, or just down the road the extensive lamb deaths from toxic weed infestation of summer forage crops are losses that could have caught anyone out, but similar losses in lambs on rocket-fuel feed is less forgivable. Such an outcome is reasonably predictable and can be avoided. Of course nitrate poisoning can crop up on less pretentious feeds when the growth conditions and the animals are correspondingly primed.

During the past three years there have been some huge animal losses due to extreme under feeding. These losses outweigh those that occur due to specific animal health issues, although it could be argued that many starved ewes were so susceptible to worms that it was an animal health issue. Exactly the same applies to breeding cows.

It is an unfortunate reflection of the sheep and beef industry that such serious animal loss outcomes can still occur despite the tools that we have available to us to predict what is ahead and/or react to what is ahead. Weather extremes, system inertia, an unco-ordinated stock movement system and fundamentally under resourced farming systems all on top of a whole variety of people issues dilute the value of those tools. These sorts of losses must be damaging to an image that we trade on and hopefully can further exploit.

Now to the point. This focus on losses due to animal health events was sparked by what seems to be a resurgence of brucellosis in breeding rams. This is truly an animal health event and one which we have largely got under control.

In my area, for example, when I began groping rams 30 years ago, this disease was rampant. Ten years ago we considered there was none. In the past two years several cases have been found as part of routine ram team examination. I am aware of the same happening in other areas, which suggests it is a systems issue.

The movement of infected carrier rams is the only vehicle by which this disease can spread from farm to farm. Though at any time there were never 100% of ram teams in an area tested, for many years none was being found in the tested ones.

What has changed? Leaking boundary fences are perhaps more common now with less maintenance being the consequence of less income. Roaming ram hoggets of the trading sort could theoretically be a risk factor. But they are hardly a new phenomenon.

I suspect that the current situation is not unlike the up and down incidence of some diseases. When the level of susceptibility is high (low immunity) then the disease is rife. As the disease spreads more and more of the mob become immune so the incidence drops.

With vigorous testing of flocks over the years the incidence of brucellosis has fallen dramatically. This leads to complacency so there is a perceived reduction in the need to test or to take evasive actions - such as buying only brucellosis-accredited free rams, or being paranoid about straying rams. It takes only a few infected rams to come into an area before it seems to show up in tested ram teams.

There is no question that infected rams have lowered fertilising power. If these rams are dominant ones the impact can be huge, given that once we are into February there are only a limited number of actions that can be taken to maximise the flock scanning result. A vital one of those actions is to have a sound ram team. Even at this late stage, having the ram team checked for general soundness including brucellosis is worth it.

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