Around the Camp: Cyber kelpie, weather and prices, don’t buy a disaster, weaner weights increase survival, management of Johne’s Disease

Quick picks: Cyber kelpie, weather and prices, don’t buy a disaster, weaner weights increase survival
Upcoming Leading Sheep events
Surveys
Deep dive: Management of Johne’s Disease
Upcoming events
Podcasts and eBulletins

Quick picks:

Cyber Kelpie: Scams, privacy, passwords, social media, software updates – protecting yourself and business online can sometimes be confusing and overwhelming. Thankfully, a Farmer’s Guide to Cybersecurity, by Charles Sturt University, is a great place to learn why it is important and what to do about it. If you need help with an incident, there’s even a Cyber Kelpie to help step you through it. Click here for more.

Weather and prices: Weather could be responsible for up to 54% of cattle and 32 % of lamb slaughter price variability over the long run. Of course, it’s more complicated than that, read more here.

Don’t buy a disaster: Just a little reminder to consider biosecurity when buying in or agisting stock – we’ve provided a quick summary for sheep here and cattle here, on some key points to consider when bringing in stock if you need a refresher. This month’s deep dive is all about one of the diseases to watch for – Ovine Johne’s disease (OJD) – so scroll down for more on how to prevent that headache.

Weaner weights ↑ survival: For our Mitchell grasslands graziers, did you know a14kg weaner has a 34% lower mortality risk than a 12kg weaner? Similarly, a small increase in weaner growth rate e.g. 0.25-0.5kg/month, can reduce mortality risk by 74%. Given it’s a good season, consider your health management to ensure it isn’t impacting growth rates. Good vaccination practices and worm egg counts to guide drenching are good places to start. Read more here.

Back to the top

Upcoming Leading Sheep events

16 July. Value your wool webinar, Online – Teams. Delivered by DPI. Register here.
8 August. Seasonal worm management presentation at National Kelpie Trials and Australian Yard Dog Competition, Dirranbandi. Delivered by DPI. More information coming soon.
Mid August. Sheep classing workshop, Bungunya. Delivered by DPI and Fox & Lillie. More information coming soon.

Surveys

Spare 10 minutes to support your industry

You could earn $200 for sharing your experience with farm management planning (including those who don’t write plans!). Find out more here.
Three times a year MLA and AWI collect wool and sheep meat industry livestock numbers and lamb production expectations, your contributions are always valuable. Complete the short survey here to make sure Queensland is counted.

Back to the top

Deep dive: Management of Johne’s Disease

Johne’s Disease is a chronic wasting disease. Johne’s has a long incubation period, with clinical signs generally not seen until around 2-3years of age (though under stress, can be as young as 9 months). The bacteria are shed through faeces (even in those not showing clinical signs) and contaminates pastures and waterways. It is then picked up by a susceptible animal (generally in the first 12months of life) when grazing/drinking. It can be spread via inclusion of infected animals (either purchased or strays), carried downhill/downstream between properties or ingested by lambs through milk from infected ewes. It causes inflammation and thickening of the intestinal lining and affects the animal’s ability to absorb nutrients leading to wasting and eventual death. Clinical signs are often worse with stress and poor nutrition. Johne’s generally appears as “tail end” of a mob that does not respond to treatment. However, there is no treatment for Johne’s once present.

Diagnosis can be difficult as it may not be until there is a larger number of cases and numerous deaths, before it is considered that Johne’s is present. Diagnosis is generally best on postmortem samples (histopathology). Faecal cultures and blood tests are also available, however false negatives can occur. Pooled faecal culturing using 1 pellet from about 350 sheep (or whole mobs if less than that number are present) is available and will generally be positive in 98% of cases if at least 2% of sheep in the flock are infected. Results can take between 2-4 months. There is no longer any abattoir monitoring available.

Once a property receives a positive result, eradication is unlikely, and producers need to learn to manage the disease to reduce the impact on production. This can be done in several ways:

Consider enterprise change/mix – fat lambs sold early will be off the property before they are likely to be showing clinical signs or shedding the bacteria.
Cull clinically affected animals – cull immediately as these are likely the higher shedders and contributing significantly to pasture contamination. This is also best done on welfare grounds. Ewes should especially be checked before joining, lambing and at marking time. This will not be completely effective, as sheep can shed bacteria without any clinical signs.
Troughs – feeding through troughs or automatic feeders reduces the chance of transmission. Water troughs can also be useful. Fencing off waterways or low-lying areas where there is likely increased contamination.
Healthy sheep – those with good nutrition, low worm burdens and overall good health will be a lot more resistant to infection (and clinical signs).
Destocking – in extreme conditions, it may be decided to destock for an extended period and restock down the track with approved vaccinates and those from SheepMAP accredited flocks. Request a National Sheep Health Declaration for all purchased stock.
Early weaning – ewes should be joined for 5 weeks only (2 cycles) to allow early weaning of all lambs. This allows for the particularly susceptible lambs to be removed from possible shedding ewes and the contaminated pastures – the biggest source of contamination. Ensure good nutrition and lower stocking densities.

Vaccination using the Gudair vaccine can be a very useful tool. It is an inactive vaccine, with lambs given a one-off dose, subcutaneously using a ¼ inch needle at 4-16 weeks of age (at lamb marking). These lambs are then considered approved vaccinates and should be marked with a V on their NLIS tag. There are safety aspects around this vaccine due to the oil adjuvant it contains and therefore the vaccine must be used with a Gudair Sekurus vaccinator gun which has a protective shroud. Vaccinated animals will generally get a lump at the site of injection. In rarer cases, the vaccine inflammatory response can infiltrate the spine causing a staggered gait that is generally not treatable. It can take 3-4 months for this to occur. However, the current recommendations on vaccine placement, injection angle and needle length greatly reduce this risk. The vaccine is highly effective, although not 100%, however, it is a valuable tool to prevent or increase the time until clinical signs are seen, reduce mortalities and reduce shedding of the bacteria. The vaccine can reduce the death rate and shedding by up to 90%. It can take a few years before improvement within the flock is noted if animals are already testing positive on the property. Vaccinating older sheep can be done, however this is less effective.

Pastures can be managed to create “low risk” pastures (like with worm management). These paddocks should be first used for weaning into, however if enough paddocks are available, can also be created for lambing. “Low risk” pastures are not to be considered free of disease. Paddocks can be grazed with steers/adult cattle (although cattle can become infected with the sheep strain of OJD), grazed with vaccinated dry sheep over 2 years of age (still some risk of shedding), rotated with cropping, re-sowing of pastures, grazed with terminal lambs sent straight to slaughter, or spelled for at least 6 months (bacteria can last in the environment for 12 months or more, especially in shaded, moist areas). Spelling can decrease the bacteria present by up to 90% each month. Paddocks up high, with few shaded gullies are less likely to have as much contamination.

Remember prevention is better than a cure (especially when there is not one). Having an up to date biosecurity plan in place, and following it, is very important. Good boundary fences to stop straying, careful purchasing of stock (from SheepMAP accredited properties, purchasing vaccinated sheep and asking for a National Sheep Health Declaration), and discussions with neighbours can all help to decrease the risk of Johne’s. If Johne’s is suspected, investigate early and consider starting vaccination as soon as possible. If the risk is considered high, consider vaccination. Keep the flocks as healthy as possible to increase resistance.

Anyone wishing to use the vaccine can only purchase through a veterinarian or vaccine reseller that has completed the Zoetis Gudair accreditation. Further information about Johne’s Disease, including training videos in use of the Gudair vaccine and Sekurus vaccinator are available on the Zoetis Livestock Solutions website.

Written by Dr Kate Burren-Wehr

Under Queensland legislation, if you become aware of the presence of this disease in any species of animal, you must report it to Biosecurity Queensland on 13 25 23.
For further information on Johne’s Disease visit the Business Queensland website.
Back to the top

Upcoming events

1, 2 or 3 July. Vegetation, Fire, Mapping and Renewables, Mitchell, Taroom or Millmerran. Register here.
7 July. Wills and estate planning in agribusiness webinar, Online – Teams. Register here.
21-22 July. Business EDGE, Longreach. Delivered by Bush Agribusiness. Register here.
22, 23 ,24 or 25 July. Veg management and mapping workshop, Blackall, Isisford, Stonehenge or Jericho. Register here.
30-31 July. GroWQ Ag Innovation Expo: Talks, Tech, Trade Displays, Longreach. Delivered by GroWQ. Information to come.
3 October. GroWQ Next Gen Event: Grassroots Growth in the Grazing Industry, Longreach. Delivered by GroWQ. Information to come.

Podcasts and eBulletins

Back to the top.