Thursday, July 7, 2022

Implement the plan

Expecting the unexpected is the age-old mantra for survival. It applies to everything or everyone to some extent, but particularly to farming. The best-laid plans get caught out by the unusual. Those plans can never capture the need for observation and awareness.

The drought aftermath has certainly thrown up some of the unexpected, particularly worm outbreaks. Weaners and hoggets have been hit by high worm challenges in many places at a time when it was starting to look like an extended drench interval was possible.

It has seemed in a lot of the cases that four weeks post-drench has been a trigger for things to start packing up. In hoggets the worm species Trichostrongylus has dominated and been devastating in some cases. Sudden dagging up and looking “off” has been a common report.

It seems this worm species gained dominance from the dry when we would have expected Haemonchus to do so. Of course moxidectin was being used extensively because of the expected Haemonchus challenge when it rained. Given that this drench is selectively persistent against different worm species, and Trich’s being the one that emerges first, this worm would have got a head start on so many farms.

For weaners the presenting picture has been the same with a four-week trigger seeming to bring scouring and lowered weight gains. There may well be some Trichs in these but these weaners have the appearance of Ostertagia. The drench choice has had an impact on what has happened on various farms and it has been clear that where there is oral combination drench containing an ML and levamisole the threat has been a lot less.

The other change to the norm from the drought has been in some trace-element levels. The two in particular that have been unusually low are copper and selenium. Following a prolonged dry the copper storage levels are usually high going into the winter. This has been the case on most farms that I see the autumn monitoring results from. On others it has been unexpectedly low.

Selenium levels most confuse me. I have seen several farms on which there is an effective selenium supplementation programme, through prills or individual animal treatments, where the levels are way lower than normal. What could be causing these unusual findings?

The dry can change the soil balance through moisture levels enhancing some elements and not others. Molybdenum is a good example. In the wet it is much more available and competes with copper uptake. So in the dry I have always expected it to be the opposite, hence often seeing high copper stores in cattle coming out of a drought. Not the case on some farms.

A factor behind these changes is the pasture species that survive during, or flourish after, a drought. Different pasture species accumulate different levels of macro and trace elements. The biggest difference is between grasses and clovers. Maybe weeds and various herbs that manage to persist and dominate also contribute.

What does all this mean? It means to be aware of the unusual and monitor more than usual. Monitoring is always the cornerstone of being in control, but expect the unexpected when the season is extreme.

The drought aftermath has certainly thrown up some of the unexpected, particularly worm outbreaks. 

I am referring to farming systems that have planned supplementation and monitoring programmes in place. To not have both is an invitation to not be in control. It is not unusual to set up some monitoring in a system that has a supplementation programme in place and to find that sufficient storage levels of these supplements is not being achieved. It is important to confirm that what is trying to be achieved is actually being achieved. Hence the value of routine monitoring, even when a planned supplementation programme is in place.

I am forever coming across situations in which supplementing is complicated and expensive. Myriad products on the market claim to effectively maintain sufficient trace-element levels. In most cases they probably do, but at a big cost. I have always considered that maintaining a sufficient trace-element status in a farming system is simple and can be done relatively cheaply. It starts with monitoring to define the status.

We know what to measure and what levels we need to be attaining. Several injectable, oral or pour-on products are available such that a cost-effective supplementation programme can be put together. Usually the simple product is enough. The claims being made for some products suggesting that they are better than the simple ones are rarely substantiated. Get independent advice.

The most common unexpected event on farms is a dead animal. While these are inevitable, in some classes of stock they can really hurt. Young stock are most at risk, but of course pregnancy creates a huge amount of risk. While the inevitability of deaths is just accepted by some farmers, there is absolutely no doubt that on farms that have a planned animal and feeding plan, and have put those plans into practice, the incidence of deaths is significantly lower than on the average farm.

A feature of high-performing farms is a low loss rate. Planning is the start and that is simple. The challenge is to implement the plan. 

Trevor Cook

Veterinarian, Manawatu


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