SELLS Animal Health Update October 2019

October 2019

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LOCAL DISEASE WATCH

Lou Baskind District Veterinarian, Palerang.

The primary focus of the district vets continues to be animal welfare, with under-feeding and malnutrition leading to ill health, starvation and compromised welfare. Straying of hungry stock is becoming a progressive problem in our region as well.

A reminder to introduce ruminants to grain and pelleted feed slowly to allow the rumen time to adapt. Sudden introduction of high carbohydrate feeds, even those that are considered safer such as brewery byproducts can cause rumen acidosis. At minimum, sudden feed introductions can affect feed conversion and production, but at worst it can cause severe illness, infections, heart failure, kidney failure, laminitis, abortions and death of stock.

New concentrated feeds should be introduced slowly over a period of 2 – 3 weeks. A roughage source must be available. More information can be found in the Managing Drought book on page 25 (cattle) and page 46 (sheep) https://www.dpi.nsw.gov.au/climate-and-emergencies/droughthub/information-and-resources/managing-drought

Animals are currently grazing in what we call the “worm zone”, where pasture is shorter than 15cm. The lowest 10cm of the plant is where the vast majority or worm larvae are picked up, so worm numbers are likely to be higher than usual for this time of year.

In those areas that received rainfall in September, worm larvae that overwintered in the dung on pasture will be active thanks to the warmth and moisture. Sheep worm egg count test results are showing Barbers Pole and scour worms. For sheep and goats, do a worm egg count (WEC) 4 – 6 weeks after that initial spring rain event to guide your treatment decisions. Monitor animals for being quieter than usual or having poor growth, weight loss, diarrhea (scours) and poor coat condition. Young cattle and bulls would typically get a chemical drench in early summer, but these may need to be administered sooner given the conditions.

Local Land Services district vets welcome questions around parasite management in livestock and can assist in interpreting the result of WECs. The WEC test kits are available at all Local Land Services office, or can be ordered online at https://www.dpi.nsw.gov.au/about-us/services/laboratory-services/kits-and-media

ANTHRAX VACCINATION

Lou Baskind District Veterinarian, Palerang.

Anthrax vaccinations are getting underway in the anthrax belt. Anthrax is a bacterial disease with serious risks to human and animal health, export markets and farm productivity. In the NSW Biosecurity Act, anthrax is Prohibited Matter, which means that everyone has a legal duty to notify if they become aware of it on their property or in their animals.

Cases of anthrax tend to occur in an area which runs through the centre of New South Wales and into Victoria (see map).

Properties that have had anthrax cases in the past are strongly encouraged to vaccinate all stock annually to prevent anthrax occurring. Those properties that are outside the anthrax belt do not require vaccination against anthrax, but we would always remain alert to the disease. The South East lies outside the anthrax belt.

Anthrax can kill stock of any age or class with no warning. Affected stock often show few or no signs of illness before they die. In some situations the disease may begin with sporadic losses of single animals over a few days, building to dramatic losses in a very short time.

All cases of sudden unexplained death in livestock should be reported to a Local Land Services district veterinarian so anthrax can be ruled out. You can find more information about anthrax here: https://www.dpi.nsw.gov.au/animals-and-livestock/pigs/health/a-z-pig-diseases/anthrax-vaccination-nsw/anthrax

SUPPORT AVAILABLE FOR PRODUCERS WITH ANIMAL WELFARE CONCERNS

South East Local Land Services’ team of district veterinarians would like to remind the community that there is support is available for land managers who may have concerns about the management or welfare of their stock as the drought continues.

“Unfortunately there have been some isolated incidents where things have gotten away from a few land managers” said South East district veterinarian team leader Dr Fiona Kelk.

“In most cases land managers have made a plan and are adapting to the conditions as they evolve and that is great to see.

“Our team of district veterinarians and agriculture advisors can help land managers make a plan for the management and welfare of their stock”.

Key things to plan for

In order to make sure the welfare of their stock is accounted for, producers need to keep on top of a few key things.

Have a plan – developing a plan is an important first step if you haven’t already done so. On the back of a dry winter and with little rain in the forecast your circumstances could change quickly in the coming weeks and months so it is important to continually assess where you’re at and have a plan of action.

Nutritional requirements – make sure you have planned so that you can afford and provide adequate nutrition for your stock. Stock have different nutritional requirements as they go through their lifecycle. The NSW DPI ‘Drought Feed Calculator’ or ‘Drought and Supplementary Feed Calculator’ Apps can help you get a clearer idea of the nutritional requirements of your stock. Your nearest Local Land Services District Veterinarian and agriculture advisor can also help you with this.

Water requirements – this is particularly important as we move through spring and into summer with little rain on the forecast and higher evaporation rates. Your nearest Local Land Services district veterinarian and agriculture advisor can help you work out a water budget and help you with an audit of the water stored on your property.

Decision making points – producers should have already identified some key decision making points in relation to the management of their stock. These decision making points should factor in your ability to keep up with the nutritional and water requirements of your stock as well as the realities of getting them to market and making sure you do so at an appropriate time so they are ‘fit to load’.

Are you bushfire ready? – with the bushfire season already underway it bears thinking about how well prepared your property is in the event of a bushfire. The team at your nearest Local Land Services office can help you understand what might be required on your property and to make a plan.

If you have any questions or would like any more information please contact the district veterinarian at your nearest Local Land Services office, or visit NSW DPI Drought Hub for a list of services and support available to you.

ANIMAL HEALTH ADVICE FOR GRAZING BRASSICAS

Alex Stephens District Veterinarian, Yass.

Some producers are in the fortunate position of having some forage brassica available for grazing and other producers are seeking advice on how to safely graze failed crops. A discussion panel was held recently at Wallendbeen Hall organised by Phil Bowden (AOF/Pulse Australia) and Sandy Biddulph with support from the DPI and Local Land Services. The aim of the day was to develop a protocol to best manage the animal health risks in sheep and cattle associated with grazing canola. Over 80 people attended, which shows the level of interest and current relevance of these issues.

Brassica crops are an excellent fodder crop of high digestibility, high metabolisable energy (ME) and high protein. Sound grazing management is essential, both to maximize plant yield and utilisation and to minimise the potential of animal health disorders. Brassica are highly digestible so it helps to think of the crop more as a concentrate, thus you need to allow the rumen time to adjust and ensure additional fiber while grazing.

The key points to avoiding animal health disorders:

• Know the grazing recommendations for your brassica variety; some crops can be grazed earlier than others.
• Ensure stock (particularly young stock) have been recently vaccinated with a 5-in-1 against clostridial diseases to avoid losses from pulpy kidney.
• Introduce animals when they are full not hungry and monitor for adverse reactions.  Monitor for signs of bloat, or nitrate toxicity (respiratory difficulty).
• Introduce animals slowly, taking them on and off for the first week to allow rumen microbes to adjust. Restrict grazing to just a few hours on the first days, then increase to unrestricted access over a week. Note that initially stock may not graze the brassica as they may need to develop a taste for it, beware that this needs to be taken into consideration for the acclimatisation period.
• Assess the nitrate risk. Nitrate risk is lower in mature crops compared to young crops. Crops grown in drought conditions may have accumulated higher nitrate levels than normal. Nitrate levels will also vary from day to day, and time of day and increase when plants are not photosynthesizing, such as during cloudy weather or in the early morning.  Consider when you last applied urea, and the rate of application and the most recent rainfall and weather. If you are at all worried, use a feed test.  Note that the stalk will have higher nitrate levels than the leaf.
• Animals will need plenty of good clean water.
• Photosensitisation is the main heath problem seen and it requires active management. It usually occurs when crops are grazed a little too early, before maturation. Younger animals have more sensitive skin and thus are more prone. This problem can be managed by monitoring sheep closely for any signs of ear swelling or blistering. Sheep affected should be promptly removed until they recover, this may involve removing all the sheep from the crop and waiting a few weeks before reintroduction, or just drafting off affected animals.
• Other rarer disorders. Stock grazing high sulphate crops can be at risk of a brain disorder called polioencephalomalacia (PEM) caused by the destruction of thiamine in the rumen. Sulphate levels can be made higher by application of Sulphur with crop establishment. Other disorders have been reported such as blindness, anaemia, goiter and digestive disorders (constipation and diarrhoea). All of these are much more likely to be seen if the brassica crop makes up more than 70% of the animal intake.
• Ensure stock are offered an alternative source of fibre while grazing the brassicas to maximise crop utilisation and minimise animal health problems.

GRASS STAGGERS

Henry Clutterbuck District Veterinarian, Goulburn.

Highlights

Cause: Ingestion of certain grasses or grass heads infected with certain fungi.

Affects: Ruminants (Sheep, Goats, Cattle).

Risks: Stock grazing pastures dominant in certain pastures during spring, summer and autumn.

Diagnosis: Clinical signs and/or post mortem by Local Land Services district veterinarian or local vet.

Treatment: Immediate removal from affected pasture. Treatment outcomes depend on toxicity. Deaths usually occur due to misadventure.

Prevention: Preparation prior to grazing and careful monitoring of stock on pastures dominant in certain grasses.

Recent rains have seen a flush of green pick come through. With this, there have been some case of grass staggers throughout the district. The term staggers covers a wide range of nervous and muscular diseases and syndromes reported by producers. These diseases can be split into 5 main groups. We focus on the group that causes staggers that are characterised as “falling-with-tremors”.

Causes of Grass Staggers

There are three main types of grasses associated with falling-with-tremours staggers. They are Phalaris spp, perennial rye grass, and paspalum.

Ingestion of certain varietals of phalaris (particularly Phalaris aquatic) containing toxic alkaloids have been associated with phalaris staggers. Removal from the pasture will result in recovery after a period of time.

Grazing of pastures dominant in perennial rye grass (Lolium perenne) is responsible for perennial rye grass staggers. The plant contains a toxin causing tremors called lolitrem B. The toxin is created by the grass when it is infected by the fungus Neotyphodium lolii. Recovery is usually spontaneous 2-3 weeks after removal from affected pastures.

Paspalum grasses (Paspalum spp) infested by the fungus Claviceps paspali also causes a staggers syndrome and is sometimes called Ergotism. A sufficiently large single dose causes signs that persist for several days. The time of onset of signs depends on the degree of the infestation of seed heads and the grazing habits of the animals. Some animals in a herd may show preference for eating the seed head and thus be more severely affected.

Diagnosis

If you suspect staggers in your flock please call your local Local Land Services district veterinarian or Local Practitioner. Diagnosis is readily achieved through post mortem.

Prevention/Treatment

Phalaris Staggers – Cobalt oral supplementation can be provided in the form of cobalt ruminal pellets, cobalt in drinking water, cobalt loose licks and blocks and cobalt drenches. Pasture spraying with cobalt sulphate in the autumn should be considered as another preventative alternative to manage the risk of phalaris staggers on high risk pastures.

Perennial rye grass Staggers – Careful monitoring of stock in perennial rye grass dominant pastures.

Paspalum Staggers – Recovery usually follows removing the animals from pastures infected with paspalum seed heads. If you have paspalum dominant pastures, Local Land Services can provide you with resources for recognising infected seed heads. Animals recover best if moved away from the paspulum, left undisturbed and provided readily available nutritious feeds.

To talk to your nearest district veterinarian contact us.