Deer Farmer: Managing Johne’s

Lynda Gray

Sean and Cassie Becker were gobsmacked when Johne’s was confirmed in their weaner mob in mid-July 2011.

The 480 weaners, trucked about 10km from the Tiroiti breeding block to Kokonga for wintering, looked fine for the first three or four weeks given the bone-dry summer and autumn. But then things started going pear-shaped with a handful starting to lose condition and some starting to scour.

When three died and another couple had to be euthanised the Beckers called in the local vet who, after taking blood samples, confirmed Johne’s.

It was a shock given that both Cassie and Sean’s families had farmed deer in the area for more than 35 years and never been affected by the insidious wasting bacterial disease. But Sean says that in retrospect the triggers were there: drought conditions which had led to grain feeding over late summer and autumn, the stress of weaning plus transport and then turn-out on to relatively lush autumn-saved grass.

The early signs of the disease were hard to pick up, he says, because at that stage there were no deer yards at the finishing block to run the deer in for close up inspection.

Their initial plan of attack was to destock the fattening block in the hope that the disease-causing Mycobacterium avium paratuberculosis (MAP) bacteria in the soil and faecal waste would die out, and also to cull suspect hinds. When neither tack worked the Beckers called in Johne’s expert and vet Mandy Bell who helped them come up with a management plan hinging largely on better feeding.

‘We could see that feeding was the easiest way to keep above the disease and we looked particularly at how, what and where we were feeding.’

“We could see that feeding was the easiest way to keep above the disease and we looked particularly at how, what and where we were feeding,” Sean says.

Advantage feeders were a key component of the plan. They spent $8800 on two 1800 litre, and two 3800 litre feeders to keep the whole barley and deer nuts up off the ground and free of the possible disease-causing MAP bacteria.

Another preventative MAP-spreading measure was the regular cleaning of water troughs and draining of some wallows to prevent deer drinking from them.

Annual blood testing of up to 20% of the hinds was recommended, but all deer were screened in 2014 which turned up 44 weaner and 23 mixed-age hind positive reactors. All were slaughtered along with a handful of other suspect animals.

“What surprised us was that all the positive hinds were big and healthy. They were super shedders.”

Since then all R2 replacement hinds have been tested and there’s been a zero tolerance for underperforming hinds.

Key facts

Sean and Cassie Becker

Sheep, cattle and deer breeding on 4000ha (3300ha effective) of dryland ranging from 450m-1400m asl. Rainfall 450mm. Farm split in four blocks in Kyeburn/Hyde areas of Maniototo:

Kokonga: 450ha flat to rolling hill country for fattening young stock.

Pigroot: 2000ha hill block for lambing ewes and wintering cows.

Lismore: 420ha of summer country.

Tiroiti: 1130ha mid-altitude hill hind breeding country

The estimated financial fallout from Johne’s over almost seven years is around $152,500

At the peak of the first outbreak in 2010 DeerPRO estimated a cost of $82,000.

“The obvious cost of deaths and poor-performing animals is substantial in these outbreaks, but the additional costs of sub-clinical disease can be significant too,” DeerPRO manager Solis Norton says.

The estimate does not include the substantial cost and labour involved with testing, although in the Becker’s case this was minimal because they assisted with Johne’s Disease Research Consortium research looking at diagnostic tests for the disease.

At the second spike in 2014/15 a $17,500 loss was calculated due to an almost 6kg drop in average carcass weight – reducing venison income by about $50 an animal – as lighter-weight and suspect animals were offloaded.

Over seven years 157 deer estimated at $53,000 were euthanised, mostly due to Johne’s.

Norton says the Beckers’ big success has been in reducing the rate of R2 hind positive reactors from 17% to less than 1%. It’s a figure Sean and Cassie are prepared to live with.

“We’re happy with the plan we’ve come up with to control Johne’s and now feel more confident in what to look out for and how to feed them to manage stress,” Sean says.

Over the next five years they want to keep pushing the better feeding plan by developing further finishing country to grow crops for finishing young stock. Improving the reproductive performance of the hinds is another goal.

“We’d like to be consistently weaning in the mid 90% (hinds to stags). We’re also keen to start looking at introducing a terminal sire.”

Although they can see the potential to push forward slaughter dates and will probably trial summer crops to improve growth rates there are limitations, Sean says.

“In a largely dryland situation it’s always dependent on the season.”

These post-rut newly weaned fawns will be winter grazed on fodder beet.

Multi-advantages

Advantage feeders were bought as part of the Johne’s-busting plan but Sean credits the 2% increase in weaning to late summer and early autumn grain and nut feeding.

Management bonuses include less grain and nut wastage, plus less time and money spent on carting supplementary feed in winter.

Grain used to be fed from a trailer every second day but a topped-up feeder will feed 250 hinds for 8-10 days. Hinds are allocated a daily allowance of 150-250g depending on the time of the year. Last year about 50 tonnes of both nuts and barley were fed from January until October.

Observation of mob dynamics has led to placement of the feeders away from water troughs so that hinds have to walk a reasonable distance for a drink, leaving less-dominant animals the chance to get their feed quota.

Barley and nuts fed from Advantage feeders also help settle sooner newly weaned fawns.

Second-hand K-line

Second-hand K-line irrigation has been put to good use. The irrigation, bought off a farmer moving to pivot irrigation, has been used to strategically water 45ha of the deer-fenced block since October last year.

Already in place was a pump shed and power used for a limited amount of hard hose irrigation so it’s been relatively cheap to get the K-line up and running. More could be added if a water take from one end of the property can be further channelled.

The biggest expense is the 45 minutes of labour required during the watering season but the results have been well worth it, a good example being the early wintering grass-saved paddocks for weaners that maintained excellent quality and cover thanks to late summer and early autumn watering.

“In a summer dry area even a small area of irrigation can make a big difference.”

DeerPRO

The progress of the Beckers’ battle with Johne’s has been analysed from kill sheet data collected and supplied free of charge by DeerPRO, formerly JML.

The rebranding of the venison processor-funded entity earlier this year was taken to highlight that it was about more than Johne’s monitoring, DeerPRO general manager Solis Norton says.

“We’re keen to get the message across that farmers can use us to get their deer slaughter data and use it to benchmark, look at trends over time and perhaps make changes based on the data.”

Johne’s monitoring would remain a core function of DeerPRO but over the next year new value-adding data applications would be investigated by quizzing farmers on exactly what kind of data, and in what form they required it.

The company was established in 2007 to monitor and collate Johne’s lesion rates and other relevant slaughter data, and point affected farmers in the right direction for support in controlling the disease. Over that time the disease had gone from exploding and causing devastation on a small number of farms to being widespread but at lower infection rates.

“It’s still there and although it’s not causing the problems it used to keeping up vigilance is important for international market assurance.”

DeerPRO gets funding of about $300,000 a year from a per-head slaughter levy collected by processors.

Cassie’s family, the Andrews, have farmed in the area since 1926. Cassie and Sean run the farm with 3.5 FTE including help from Cassie’s dad David.

Stock wintered

Sheep (Corriedale-Romney)

9800 ewes

2500 hoggets

Cattle (mostly Angus-Hereford)

90 breeding cows

160 MS weaners

250 R2 steers

Deer (Red)

715 MA hinds

50 R2 hinds

560 weaners

The Beckers’ Johne’s management plan

Advantage feeders to keep grain and nuts off the ground.

Regular cleaning of stock water troughs and exclusion from wallows where possible.

Purchase of Johne’s-resilient stags from Peel Forest Estate.

Annual blood-testing of R2 replacement hinds.

Recommended-industry triple drenching combo for internal parasite control.

lyndagray@xtra.co.nz

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