Animal health Hunter - lls.nsw.gov.au · Animal health advice for producers in theHunter Contents...

Alert: eNVD problemLivestock producers using electronic versions of the National Vendor Declaration forms (eNVDs) should be aware that there is a problem with the formatting of the document which results in the electronic signature being microscopic in size when the eNVD is printed out. Consequently, it looks as though the eNVD hasn’t been signed. This has caused problems at saleyards and particularly at meatworks, where all sections of NVDs are scrupulously checked for completeness.

Integrity Systems (managers of the NVD system) are aware of the problem, but advise that it may take some time to correct. In the meantime, those using eNVDs should check the document once it has been printed and manually sign it in the space provided for the electronic signature.

Local Land Serviceswww.lls.nsw.gov.au

We help secure the future of agriculture and the environment for NSW communities

Spring 2020

Animal health advice for producers in the

HunterContentsCALF SCOURS IN BEEF HERDS ..................................................................1

CALF SCOURS PREVENTION PLAN .............................................................3

DID YOU BUY QLD HAY DURING THE DROUGHT? .........................................4

TICKS CAN ALSO AFFECT PEOPLE ..............................................................4

HORSE TSS NOW AVAILABLE ONLINE ........................................................7

SALMONELLA ENTERITIDIS UPDATE ..........................................................8

AVIAN INFLUENZA INCURSION IN VICTORIA .............................................9

CHICKEN BIOSECURITY (NSW DPI) .........................................................10

AVIAN INFLUENZA EXCLUSION IN THE HUNTER ........................................10

VACCINATE NOW TO PROTECT LIVESTOCK FROM ANTHRAX ........................ 11

BUYING NEW STOCK: QUARANTINE AND BIOSECURITY .............................. 12

AFRICAN HORSE SICKNESS .................................................................... 14

BLUE GREEN ALGAE PROJECT ................................................................. 15

HELPING PRODUCERS RECOVER FROM BUSHFIRE ..................................... 16

BOVINE EPHEMERAL FEVER (BEF) VACCINATION CONSIDERATIONS ............ 16

UNUSUAL PNEUMONIA AND EMPHYSEMA IN BEF INFECTED CATTLE ............18

BLUETONGUE VIRUS ZONE EXTENDED .................................................... 19

DISEASE INVESTIGATION - A “dog sitting” Bull .......................................20

CALF SCOURS IN BEEF HERDSCalf scours is most common in beef calves during the first six weeks of life. A scours outbreak can be time consuming, expensive to treat and, if not managed correctly, can result in significant losses (up to 10% of calves born).

During the autumn calving period 2020 multiple beef herds in the Hunter had issues with scours in calves under six weeks of age. Losses ranged from 5-10% of calves and there were varied causative organisms, including more than one organism on the same property. Most of the cases coincided with calving during wet weather periods.

With weather forecasts suggesting a La Nina event with higher than normal rainfall over the rest of 2020 and early 2021 the likelihood of developing scours in beef calves during the spring calving is increased.

Calf scours are due to a combination of predisposing environmental conditions and infectious organisms. More than one organism can be present in the one calf during a particular outbreak. During autumn, different properties had different organisms, including some unusual Salmonella species rarely seen in cattle.

It is important to remember that several of these organisms are zoonoses and can cause diarrhoea in people. Care must be taken when treating sick calves to use disposable gloves and overalls to prevent contamination of clothes and to disinfect hands and equipment appropriately. Contaminated overalls should be washed separately to the family wash.

Common pathogens which cause calf scours include:

• Cryptosporidia

• Rotavirus

• Bovine coronavirus

• E. coli

• Salmonella

2 | Animal Health – Spring 2020

These pathogens are shed in low, but increasing, numbers in the manure of cows around the time of calving, and in much greater numbers in the manure of scouring calves and unaffected calves up to six months of age. The younger the calf, the smaller the dose required to produce disease.

Calves rely on the ingestion of colostrum in the first 24 hours to provide antibodies against organisms they will encounter in their environment. They are not able produce their own antibodies for a couple of months. Therefore, we rely on the cows producing good quality colostrum, containing antibodies to the organisms of the local environment, and enhanced by vaccination, to provide protection for the calves. Failure of this passive transfer of immunity can be caused by cold wet conditions decreasing drinking during the first 24 hours; cows not vaccinated or being brought onto the property in late pregnancy with insufficient time to respond to local organisms; organisms entering the bloodstream through umbilical chords that do not get time to dry out due to wet conditions; heavily contaminated paddocks being used for calving every year; cows that are immunosuppressed due to very low selenium or copper; and dystocia, or calving difficulties.

Treatment of affected calves is difficult, as, often, producers are not able to catch calves to treat them until they are severely ill and often beyond responding effectively. It relies on rehydrating the calf, meeting the energy requirements of the calf, providing a warm dry environment and use of antibiotics if indicated. Some producers put portable panel “pens” in the

paddock that allow the cow to sniff the calf over the pen but allow the calf to be easily caught and treated. This separation should be for no longer than 24- 36 hours maximum but can be associated with increased mastitis and mismothering depending on conditions.

If calves are still suckling then avoid electrolyte solutions with high levels of bicarbonate or citrate as these will impair milk clot development in the abomasum. Those with acetate or proprionate are better. Your vet can advise you on the best electrolyte for your situation.

Not all scours require antibiotics as they may be viral infections, so it is worthwhile contacting a vet to organise identification of the cause.

As it is difficult to control the disease once calves start to scour and become sick it is important to manage calving herds to avoid outbreaks. Vaccine against coronavirus, rotavirus and E.coli is available to be given to cows prior to calving and can be of benefit in assisting prevention of scours through colostral antibodies. However, management of other predisposing factors is also important. One of the herds we assisted had had previous issues with scours caused by rotavirus and coronavirus for which they now vaccinate the cows, and this year had an outbreak of Salmonella and cryptosporidium (although testing showed prevention of rotavirus and coronavirus had been effective).

Animal Health – Spring 2020 | 3

The following table provides some good management advice for prevention of scours in calves

CALF SCOURS PREVENTION PLAN• Limit stock introductions, vaccinate and follow strategic

drench recommendations.

• Select bulls for ease of calving and manage short joining/calving period.

• Manage heifers as separate mob.

• Use protected calving paddocks, with low stocking density and easy access to feed, water and supplements.

• Rotate calving paddock from year to year to reduce build-up of infectious organisms. Some organisms can live in the ground for up to 12 months.

• Move calved cows with their calves through to clean paddocks after calving.

• Do not mix age groups of calves until greater than four weeks of age.

• Avoid yarding calving cows or heifers unless calving assistance is needed. This limits the opportunity for spread of scour organisms to newborn calves.

• Limit time assisted calves are held around the yards.

• Clean crush areas and flush with a disinfectant after each use.

• If a scour outbreak occurs, hold and treat affected calves in a mobile calf pen (providing warmth and shade) in the paddock away from ‘cow camps’ but near their mothers.

• Avoid calving over summer as cattle gathering under shade trees creates conditions of close contact which allows spread of scour-causing organisms by flies and direct contact. In addition, increased temperatures mean calves die of dehydration more rapidly.

Table courtesy of Dept of Primary Industry and Regional Development,

Western Australia. (with addition)

4 | Animal Health – Winter 2020

DID YOU BUY QLD HAY DURING THE DROUGHT?Check you didn’t also bring in Cattle Ticks

Hay brought from non-traditional hay suppliers can create a biosecurity risk for your farm. Please be on the alert for cattle tick, following the drought and vast quantities of hay moved around Australia.

Cattle Tick can hitch a ride on hay if the Hay is cut from a property that is in the tick zone and they also have livestock that can carry cattle tick. This situation was also seen during the drought with farm cats on western NSW properties, sleeping on brought in hay and succumbing to Paralysis tick (way outside of the distribution of the coastal Paralysis tick).

Department of Primary Industries have advised that during this year’s investigations into properties detected with cattle ticks in the Tweed/Lismore region it was discovered that a number of properties did not show obvious transmission pathways of cattle ticks (ie normally transmission comes from straying or introduced livestock), however, property owners had purchased large amounts of hay during the drought. Investigations have found a far NSW North Coast based rural supplier had purchased low grade hay which may have been sourced from high risk tick areas of the QLD tick infested zone.

Due to the intense demand for Hay during the drought, there is the risk hay could have been harvested from any available paddocks and possibly also roadsides in tick infested zones.

Much of this low-grade feed was not plastic wrapped but wrapped in mesh which would allow the survival of cattle tick larvae. This feed would often also be used immediately upon delivery to NSW properties, further enhancing the risk.

There is some concern that hay of this nature could have been sold to rural suppliers or direct to farmers into NSW.

If you are not sure of the origin of purchased hay, please monitor your stock for signs of cattle tick fever which is anaemic (pale or yellowed memranes), feverish, lethargic cattle, often with red brown urine or they might just be found dead. Cattle Tick fever is carried by the Cattle Tick Boophilus Microplus.

Paralysis and Bush tick numbers have increased this last month with the appearance of warm weather and moisture, thus there is opportunity for tick fever if cattle ticks carrying tick fever were introduced during the drought.

If you have any concerns please call your District Veterinarian on 1300 795 299.

TICKS CAN ALSO AFFECT PEOPLESpring and Summer is a high-risk period for the adult Australian paralysis tick, Ixodes holocyclus. The following information on tick bite prevention and tick removal is included as a reminder to protect yourself from tick bites.

The bite from Ixodes holocyclus can:

1. induce paralysis in humans (rare), companion animals and small livestock,

2. induce life threatening allergic reactions in people, lead to the development of Mammalian Meat Allergy (MMA), lead to the transmission of Rickettsia australis; commonly known as Queensland Tick Typhus (QTT).

Information on several soon to be released papers by Australian Researchers highlights the following take home messages regarding tick repellents and tick removal.

Helpful hints for protecting yourself against ticks

Wide-brimmed hat (to help when bending over near tick

infested bushes)

Shirt collar up and/or use tickicide (permethrin)-

treated scarf

Spray repellent on bare skin and clothes where

there are gaps or openings

Shirt tucked into pants

Long pants tucked into socks

Long sleeve with all buttons done up

Light coloured clothing (so ticks are easier to see)

Tuck hair in under hat or tie back (ticks are headed

for your hearline)

Re-apply repellents according to the manufacturer’s instructions

Consider using tickicide (permethrin)-treated clothing

Remember to check yourself regularly

THE AUTHORS ACKNOWLEDGE THE CONTRIBUTION OF CHRIS WILLIAMS, WILLOUGHBY COUNCIL, TO THE ORIGINAL VERSION OF THIS IMAGE.

Animal Health – Winter 2020 | 5

Repellents

• DEET, Picaridin and Oil of Lemon Eucalyptus provided protection in repelling ticks for four hours. Only DEET provided 100% protection for 4 hours.

• Spatial repellents failed to repel Ixodes holocyclus.

• Permethrin treated clothing can help prevent tick bite.

• Pre-impregnated clothing lose a large amount of their effectiveness within 30 washes (although this depends on the type of fabric that the clothing is made from).

• Pre-impregnated fabric retained effectiveness for longer than DIY treated fabric kit. DIY treated fabric should be re-impregnated after laundering.

Tick removal take home messages for the Australian Tick (Ixodes Holocyclus):

• Removal of Ixodes holocyclus via tweezers (or other forcible means) substantially increases the risk of an adverse reaction in humans,

• Killing a tick in situ substantially reduces the risk of any allergic reaction developing in the patient.

• The attached ticks can be effectively killed with the use of a permethrin based cream (Lyclear is the only product available) or ether based sprays that are used for treating skin tags and warts.

Note that there is one ether based product, Tick Off, that is registered with the TGA for killing attached ticks in situ.

The tick killing procedure has now been adopted by the clinical experts in the field, namely the Australasian Society of Clinical Immunology and Allergy.

Two common ticks and disease syndromes to watch for

“The warm weather and recent rain of Spring has seen a substantial increase in tick related issues in livestock. The region experienced a holiday from ticks during the drought but they have reappeared with a vengeance over the last few months.

Young and newborn calves, small ruminants and companion animals are at most risk of being affected by the Paralysis tick (Ixodes Holocyclus). Paralysis tick intoxication can appear within 3-5 days of tick attachment.

Cattle recently introduced to the coast from non-theileria areas and homebred calves are at risk of succumbing to anaemia from Theileria. Theileria is a red blood cell parasite carried by the Bush Tick (Haemophysalis Longicornis). We are seeing an increase in Theileria affected homebred calves at the moment. Please monitor calves from 6-8 weeks of age for lethargy caused by anaemia. Management tips are available at https://www.dpi.nsw.gov.au/__data/assets/pdf_file/0011/723917/Ticks-of-concern-to-NSW-stockowners.pdf#:~:text=Animal%20Biosecurity%20and%20Welfare%2C%20NSW%20DPI%20The%20three,serious%20economic%20damage%20to%20beef%20and%20dairy%20production.

Please check out the latest advice from our Agricultural Extension Team’s Spring Newsletter here:

Hunter LLS puts together a feed availability and costing report monthly that is available to livestock owners. These reports give a general idea of current feed availability and pricing that will assist in making on farm decisions. For further details and to discuss your individual livestock and pasture needs, please contact Hunter LLS: Livestock officer, Teresa Hogan on Ph: 0417352694 or email: [email protected]

Household

tweezers

are tick

squeezers

“”

NEVER twist or pull out a tick with

tweezers or other devices

“”

“ ”Freeze don’t

squeeze

lls.nsw.gov.au/regions/hunter/newsletters

Subscribe Here

Hunter Local Land Services

LOW STRESS STOCK HANDLING WORKSHOPSWant to learn advanced stock handling methods that will improve your profits, the wellbeing of your stock and the ease of movement in emergencies

GRAHAME REES is an industry leader in low stress handling techniques and Hunter Local Land Services is bringing him to our region to run three courses for local beef and dairy producers, farm managers and rural workers.

Registrations are essential, with fees substantially subsidised for the two-day workshop. Numbers limited to 25 participants at each location.

This a fantastic training opportunity. Don’t miss it! Participation is free for producers affected by the 2019 fires.

DatesMid Coast: Saturday 23 and Sunday 24, January 2021 Wednesday 3 and Thursday, 4 February 2021 Saturday 6 and Sunday 7, February 2021Last week of March (TBA)Stock agents and saleyard staff enquiries welcome please contact Lyndell Stone on the RSVP details.

To register for a workshop please email [email protected]

For general enquiries contact Lyndell Stone 0429 532 855

RSVP


TRANSPORTED STOCK STATEMENTS FOR HORSE MOVEMENTS NOW AVAILABLE ONLINERecording the movements of your horse has just become easier for recreational horse owners, with Transported Stock Statements (TSS) for Horse Movements now available online and free to download from the Local Land Services website.

Transported Stock Statements for Horse Movements are necessary for tracing horse movements for biosecurity purposes and are also useful in helping the NSW Police identify stock theft. Scott Ison, Business Partner for Animal Biosecurity and Welfare with Local Land Services, said the NSW Government has listened to horse owners, who were seeking an easily accessible form, to help them meet their biosecurity responsibilities.

“Transported Stock Statements for recording horse movements are not a new requirement, and it is essential horse owners understand how and when they need to use a TSS,” said Scott. “We’re making it easier for horse owners to access these important forms by making a new dedicated Transported Stock Statement for Horse Movement available online, and free to download.

“This new form does not have a serial number, so horse owners can print it, share it electronically or even photocopy the form to ensure they always have a copy on hand at times like going for a trail ride, taking their horse to a riding lesson or even to see the farrier.”

This dedicated TSS for Horse Movement (without a serial number), cannot be used for transporting any other type of livestock as it does not meet National Livestock Identification System (NLIS) requirements. Previously purchased TSS forms

or TSS Booklets are still eligible to use for recording the movements of horses or other livestock. It is also important to note if you are making a return trip on the same day you only need to complete one form.

There are a number of exemptions including horses being transported for work such as mustering, horse riding events such as pony club or shows, or the transportation of race horses or harness racing horses. People are encouraged to carry proof of the exemption as they may need to present it to Police on request. People are advised to use a TSS if they are in doubt. Presently there is an increased focus on ensuring horse owners are complying with TSS requirements.

“NSW Police launched Operation Stock Check in August 2020 resulting in more monitoring of people trucking horses and other livestock around NSW,” said Scott.

“Be prepared, you are likely to be pulled over and asked by the NSW Police for a TSS for the horse you may be moving.

“If you do not have a TSS with you or your horse does not meet any of the exemptions, you may be fined.”

For more information on when you need a TSS for Horse Movement click here. www.lls.nsw.gov.au/help-and-advice/livestock-health-and-production/moving-and-selling-livestock

Download a copy of the form here. www.lls.nsw.gov.au/__data/assets/pdf_file/0009/1259964/Transported-Stock-Statement-for-Horse-Movements-fillable-form.pdf


Salmonella is a common bacterium found in animals, including poultry. When humans consume food contaminated with Salmonella it can lead to severe illness including gastroenteritis. Salmonella enteritidis (SE) had not been detected in NSW poultry until September 2018, where it was linked to foodborne illness in humans. SE can spread from property to property through movements of birds, eggs, manure, produce, equipment, feed, rodents, people and vehicles. Since the first detection of SE in NSW linked to a poultry facility there has been a further 16 NSW poultry egg facilities and five Victorian poultry egg facilities. NSW government agencies have been working collaboratively to identify the source and stop the spread of SE. Steps were immediately taken to prevent consumer exposure to SE with movement restriction, decontamination, improved biosecurity, trade recalls, product withdrawals, consumer advisory material with media and continued surveillance. More information on SE can be found at www.dpi.nsw.gov.au/animals-and-livestock/poultry-and-birds/health-disease/salmonella-enteritidis

NSW DPI has issued a Biosecurity (SE) Control Order to assist in the management of the biosecurity risk posed by the spread of Salmonella enteritidis (SE) www.dpi.nsw.gov.au/__data/assets/pdf_file/0019/1149400/Biosecurity-SalmonellaEnteritidis-Control-Order-30-June-2020.pdf. In July 2020, all licensed egg businesses (including grading and packing facilities) in NSW were informed by the NSW DPI and NSW Food Authority that they had to conduct mandatory testing for Salmonella enteritidis (SE) with the first round of testing to be done by the 1st October 2020. This SE mandatory testing is to be conducted every 12-15 weeks with NSW DPI covering the cost of the testing for the next two years. Licensed producers that do not comply with the control order

could face significant penalties, including infringement notices, fines and possible prosecution. Testing is not required on pullet rearing facilities, breeder farms and chicken meat farms unless they also produce and sell eggs in NSW.

NSW DPI encourage egg producers to join the voluntary National Salmonella Monitoring and Accreditation Program (NSEMAP) as a proven, low cost way of ensuring flocks are free of SE. Approximately 75% of NSW layer hens are already tested for SE under the voluntary NSEMAP. For more information on NSEMAP visit www.dpi.nsw.gov.au/__data/assets/pdf_file/0020/722081/NSEMAP-Guidelines.pdf . Otherwise undertake sampling and testing in accordance with NSW DPI guidelines every 12-15 weeks. All information of testing requirements is in the Biosecurity (SE) Control Order guidelines https://www.dpi.nsw.gov.au/__data/assets/pdf_file/0006/1252482/16334-Salmonella-Control-Order-Guide_FINAL-10082020-2039.pdf. By bringing the testing up to 100% will be of enormous benefit in managing SE in NSW.

Many producers may have several questions with regards to SE Testing and more information can be found in www.dpi.nsw.gov.au/__data/assets/pdf_file/0003/1252938/SEFAQS.pdf , and the DPI SE page https://www.dpi.nsw.gov.au/animals-and-livestock/poultry-and-birds/health-disease/salmonella-enteritidis which includes other resources that may be required. If you have any further questions, please contact your Local Land Service District Veterinarian and we can assist.

Joanna Blunden is the Development Officer (Poultry Eggs) for the NSW DPI based out of Tocal. Joanna is another excellent resource for Poultry Egg Industry Updates and any questions with regards to SE testing. Joanna is always willing to assist and her contact details are Ph: 0427 408465 or email: [email protected]

SALMONELLA ENTERITIDIS UPDATE

https://www.dpi.nsw.gov.au/__data/assets/pdf_file/0020/722081/NSEMAP-Guidelines.pdfhttps://www.dpi.nsw.gov.au/__data/assets/pdf_file/0020/722081/NSEMAP-Guidelines.pdfhttps://www.dpi.nsw.gov.au/__data/assets/pdf_file/0003/1252938/SEFAQS.pdfhttps://www.dpi.nsw.gov.au/__data/assets/pdf_file/0003/1252938/SEFAQS.pdfhttps://www.dpi.nsw.gov.au/animals-and-livestock/poultry-and-birds/health-disease/salmonella-enteritidishttps://www.dpi.nsw.gov.au/animals-and-livestock/poultry-and-birds/health-disease/salmonella-enteritidishttps://www.dpi.nsw.gov.au/animals-and-livestock/poultry-and-birds/health-disease/salmonella-enteritidishttps://www.dpi.nsw.gov.au/animals-and-livestock/poultry-and-birds/health-disease/salmonella-enteritidismailto:[email protected]


AVIAN INFLUENZA INCURSION IN VICTORIA When an outbreak of Avian Influenza occurs, procedures are in place to respond and eradicate the disease. This involves slaughter of the infected and in-contact poultry, decontamination, strict quarantine, movement controls to prevent spread, tracing and surveillance to locate the extent of further infections.

Avian influenza is a notifiable disease and if you are concerned that your poultry are showing the above clinical signs then legally you are required to notify your Local Land Service Office, private veterinarian or the Emergency Animal Disease Hotline on 1800 675 888.

Strict Biosecurity measures can help prevent outbreaks of avian influenza in your birds. Try to prevent wild birds having contact with your domestic birds and regular cleaning of food and water containers. Ensure strict quarantine measures are put in place for any new introductions.

NSW Department of Primary Industries have written the next article about Chicken Biosecurity in order to assist you with disease prevention in your chickens.

For more information on Avian Influenza in Victoria, click on the following link https://agriculture.vic.gov.au/biosecurity/animal-diseases/poultry-diseases/avian-influenza-bird-flu#h2-1

Avian Influenza (AI) is commonly referred to as ‘Bird Flu’ and is a highly contagious viral infection of birds. Poultry, ducks, geese, turkeys, guinea fowl, quail, pheasants, emus and ostriches are most susceptible to being infected by avian influenza. Many wild birds, including waterfowl and seabirds can carry the virus and show no clinical signs of disease. Infected birds shed AI virus in their saliva, nasal secretions and faeces and disease can occur when infected wild birds have contact with domestic birds, or indirectly through contaminated water and feed containers.

Clinical signs that are seen with avian influenza in birds include; sudden death, respiratory distress, swelling of the head, purple discolouration of the comb and wattle, coughing, sneezing, rasping breathing, decrease in water and feed intake, decreased egg production, ruffled feathers, depressed, closed eyes, diarrhoea and occasional nervous signs.

On the 31st July 2020, there was a confirmed outbreak of highly pathogenic avian influenza (H7N7) in Victoria. This infected premises and surrounding region was placed under movement restrictions for the purpose of disease control. Since the initial detection of highly pathogenic avian influenza there have been three detections of low pathogenic avian influenza (H5N2 and H7N6) on two turkey farms and one emu farm within Victoria. The last detection of Low pathogenic avian influenza was on the 23rd August 2020.

CHICKEN BIOSECURITY (NSW DPI) Many people have discovered the joys of poultry ownership as we spend more time at home.

But even if you’ve had backyard poultry for many years it’s worth brushing up on the basics of biosecurity and responsible ownership.

Below we outline some steps you can take to keep your poultry happy and healthy, plus help protect our poultry producers.

Prevent your chickens or poultry from accessing open dams, lakes, creeks or other watercourses where wild birds congregate.

Excluding your birds from these areas reduces the risk of contracting disease from wild birds.

Quarantining new poultry until you’re sure they are disease free

A minimum quarantine period of 30 days is recommended and birds should be housed in an area completely separate to the flock and an area that is not used for any other purpose.

A distance of 10 metres from the main flock is enough to prevent aerosol transfer of most diseases. Use separate food and water dishes and food storage containers to those used in the main run.

Purchasing from accredited, reputable sources means you can have greater confidence that you’re not bringing home pests and disease.

Separating poultry, including feed and water, from wild birds

Housing and intermingling with wild birds is one of the key risks for the introduction of diseases like avian influenza. Wire mesh of 10mm × 20mm will exclude most wild birds, including small birds like sparrows.

It’s important to remember that wild birds will be especially attracted to feed and water so take extra precautions to ensure they can not access these areas.

Practising good hygiene at all times

Regularly clean and disinfect feed and water containers, don’t share equipment with other birdkeepers unless it’s been cleaned and disinfected, and clean concrete floors, walls and aviary wire regularly

Wash hands after handling animals and birds, and before preparing or eating food or smoking. Unwashed hands should not be put near the mouth.

Minimise visitors to your poultry. If people do visit ensure they wear clean shoes.

For more information on keeping poultry visit www.dpi.nsw.gov.au/animals-and-livestock/poultry-and-birds or https://www.australianeggs.org.au/news/biosecurity-for-backyard-chooks/

AVIAN INFLUENZA EXCLUSION IN THE HUNTER A local producer introduced a breeding group of chickens from South Australia in July. These chickens had originally come from Victoria in December and had shown respiratory symptoms on arrival. On arrival in the Hunter, the rooster had watery eyes but no other issues. The birds were quarantined from the home birds and the rooster was treated and isolated for one week. After the week, the rooster appeared well and was introduced back to the hens for breeding. Eggs were collected and placed in an incubator.

Unfortunately, the rooster started to become unwell again, with respiratory symptoms such as mouth breathing, weight loss, watery eyes and despite treatment with antibiotics the rooster died. During September the chicks hatched in the incubator and appeared to have conjunctivitis within a few days, they failed to thrive, and one chick died.

This chick was submitted to the Local Land Services for Avian Influenza exclusion, Newcastle Disease exclusion and Infectious Laryngotracheitis exclusion. Further testing is being carried out to establish the cause of death.

This case is a perfect example of quarantining new birds on arrival, until you can feel safe that they are disease free otherwise it can be devastating to your entire flock.



VACCINATE NOW TO PROTECT LIVESTOCK FROM ANTHRAX

NSW Department of Primary Industries (DPI) and Local Land Services (LLS) have urged farmers to vaccinate cattle and sheep against anthrax, to prevent the disease which can kill livestock.

DPI senior veterinary officer, Graham Bailey, said anthrax is unpredictable and affected stock often show few or no signs of ill health before they die.

“Annual vaccination should be considered on high-risk properties as anthrax can lie dormant in the soil for decades,” Dr Bailey said.

“High-risk properties include those where anthrax has been detected and nearby properties.

“In NSW, anthrax tends to occur in an area which runs through the centre of the state between Bourke and Moree in the north, to Albury and Deniliquin in the south.”

Farmers can contact LLS to obtain specific advice for their properties.

Vaccination prevents anthrax, which is caused by the bacterium Bacillus anthracis, from occurring and breaks the cycle of spore production to reduce the risk of anthrax occurring in the future.

When vaccination is conducted on an annual basis, spores in the environment die.

The last case of anthrax detected in NSW was in January 2020.

LLS Animal Biosecurity and Welfare business partner, Scott Ison, said farmers can apply to use the anthrax vaccine through their LLS district veterinarian.

“Only authorised applicants can place an order for the vaccine with their local rural supplier or private veterinarian,” Dr Ison said.

“Farmers should suspect anthrax as a possible cause if animals die suddenly. There may be no signs and the disease can begin with sporadic deaths of single animals over a few days before building to dramatic losses in a very short time.

“Cases of sudden death in livestock are regularly investigated by LLS and private veterinarians and in most cases anthrax is excluded as the cause.”

Anthrax, a notifiable disease which must be reported immediately to the Emergency Animal Disease Hotline by calling 1800 675 888, is listed as prohibited matter under the NSW Biosecurity Act.

Information about preventing anthrax is available on the DPI website or from LLS, 1300 795 299.

12 | Animal Health – Winter 2020

These new arrivals should be quarantined for at least three weeks, so you need to determine if this area is suitable for this length of time. Does it have easy access to the yards if you need to drench or vaccinate? Is it large enough for the number of new arrivals? Is it suitable if it is very hot or if it rains heavily during this time? Always take care of your current herd before taking care of the animals in quarantine. This will help to reduce the amount of possible cross contamination. Do you have a single family member or staff member that can look after the quarantine animals only?

Animal Health

Buying in cattle is common practice on many farms. But whether you are sourcing a single bull or replacement heifers, you also risk bringing disease onto your farm. Quarantining animals coming onto your farm is essential if you want to avoid introducing disease. It also protects the incoming stock from some of the challenges they may face when they join your herd.

Did you get a National Cattle Health Declaration? It gives you some very important and relevant information. It tells you if the cattle were born on that property or if they were bought in. It tells you if the property has a Biosecurity Plan and whether the cattle have been tested for certain diseases. It also lists the most recent drench including the date and product used and which vaccinations these cattle have previously received. The Cattle Health Declaration is a legal document. While this document is not compulsory, it is highly recommended that you request one whenever you buy cattle and provide one when selling them. This gives important information about the cattle being purchased and any associated health risks. This Cattle Health Declaration should accompany the National Vendor Declaration.

Try and only purchase stock that you know are free of infectious diseases. You need to try and quarantine all introduced animals until you are sure that they are disease-free. You don’t want to risk spreading any diseases through your herd.

The age and type of animals purchased will determine what quarantine treatments they require. All animals should be drenched and receive a 5-in-1 or 7-in-1 vaccine. Have you purchased animals from an area where ticks are prevalent? What do you need to do to treat them? Do you have ticks at your property? Have these animals previously been exposed to ticks? Is Theileria a risk? Have you bought bulls? Do they need to be vaccinated for vibriosis or for Three day sickness?

Which drench is most appropriate? This depends on where you are located, as you want to use effective drenches to prevent the introduction of internal parasites and fluke as well as external parasites, if required. Faecal egg counts (including fluke) should be done 10 days post drenching to ensure the treatment you gave was effective. This is essential before moving the cattle from the quarantine area. If you believe the

BUYING NEW STOCK: QUARANTINE AND BIOSECURITYAs we continue to receive very welcome rainfall and pasture begins to grow again, many people are looking at re-stocking. There are several important things that you need to consider prior to bringing new stock onto your property.

Sourcing Stock and Planning the Quarantine Area

Before you purchase new stock there are several things that you need to consider. Planning at this stage is essential. This should all be part of your Biosecurity Plan. What type of stock are you buying? Are there cows in calf? Do they require any additional care? Bulls? Proven cows? Heifers (less disease potentially)? Replacement stock? Or young stock to grow and sell?

Where are the stock coming from? Locally from saleyards or private sale? Online auctions (all from one place or from several different places)? Out of area – what diseases might they have that we don’t have here? Are the cattle being transported by yourself? What are you using to clean and disinfect your truck? Or are you using a commercial transporter? Are they transporting your cattle only or will there be other cattle on the same truck as well?

The National Livestock Identification System (NLIS) is Australia’s system for the identification and traceability of cattle, sheep and goats. It is essential for biosecurity, food safety and market access internationally that we all do our part and ensure that all livestock movements are recorded on the database. All cattle must have NLIS accredited tags or devices from their property (PIC) of birth. This tag will remain with the animal for their entire life. It is illegal to remove this tag. When you buy cattle from another property, its original tag will remain with it for life. If tags are lost, post breeder tags (with your PIC) must be used. This indicates that this animal will no longer have ‘lifetime’ traceability.

It is essential that you have your Quarantine Area ready prior to the arrival of the cattle. It needs to be far away from the area where the current herd is living. It must be a separate paddock or yards. There should not be a shared fence line or shared water source/trough (make sure your fences are all stock-proof). It is best to have the quarantine area down slope and downwind so that any contaminated manure or aerolised pathogens are not moving into areas where your healthy animals are kept. There must be designated equipment and boots/overalls (no utes or quads into this area/paddock, unless they are not needed anywhere else on the farm). If you don’t have multiple pairs of boots, buy some cheap gumboots. Gumboots are great as being all rubber they can easily be cleaned and are not ruined by constantly stepping in footbaths. If necessary use disposable boot covers. You must practice good hygiene and always wash hands directly after leaving the quarantine area.


animals were drenched recently prior to purchase and you do not want to drench them again, doing a faecal egg count will tell you if previous treatments were effective.

These new arrivals should be checked at least daily for any signs of disease. You are keeping an eye on their body condition and are looking for any signs of lameness, signs of skin disease, panting, nasal discharge, coughing or any changes to their eyes. Observe their feed and water intake and the amount and consistency of their manure. Look for any changes in behaviour. If one lags behind and doesn’t come up for food, or isn’t with the rest of the herd, this may indicate that something isn’t right. If one has an eye that isn’t fully open or is weeping a little bit, this may be an early sign of pink eye. Ensure all staff responsible for the care of the livestock know how to identify sick and injured animals.

on the property. Purchase stock with the same, or higher, health status as your own. Insist on a Cattle Health Declaration. Use a TruckSafe Animal Welfare accredited transporter to carry the livestock – vehicles can contaminate properties. Limit the movement of non-property vehicles. Ensure records of stock transactions and movements are kept up to date. Quarantine and monitor new livestock for at least 21 days. Check the faecal egg count of new stock 10-14 days after arrival/drenching to ensure all gastrointestinal worms have been removed. Control any access by feral animals and work with neighbours to maximise effectiveness. Dispose of carcasses in an area where other livestock and feral animals cannot access them. Avoid environmental contamination with carcasses. If an animal dies while in quarantine and the cause is not obvious, contact your vet to conduct a post mortem. Monitor and manage vermin, feral animals, weeds and wildlife populations to prevent impact on stock. Erect signs so that there is no confusion as to which is the quarantine area, so that no one mistakenly enters.

Depending on where the cattle have come from will determine if they may be bringing any specific weeds or diseases onto your property. This is why it is essential to keep cattle in a yard or quarantine area to ensure any internal parasites are expelled, but also any seeds. This is especially important if buying cattle from further away or interstate. Know which weeds are most significant in your area and which to look out for if buying cattle in from other areas. Know which weeds can cause animal health issues. It is important to be able to identify weeds such as green cestrum and mother of millions, which are toxic and can be fatal to livestock.

Feeding

Source stockfeed from a reputable supplier that operates under a quality assurance program. Always ask for a Commodity Vendor Declaration or Fodder Declaration. Try and source stockfeed locally. Ensure that you do not feed restricted animal material (RAM) to ruminants, as this has led to the introduction of Bovine Spongiform Encephalitis (BSE) and Foot and Mouth Disease (FMD) in other countries. Ensure stockfeed is not contaminated by domestic animals, feral animals or vermin. Keep feed in a dry, clean area. Inspect it prior to feeding out. Keep troughs clean and ensure there is easy access to watering points. Try and limit access to watering points of feral animals that may carry disease. Ask what cattle were fed prior to being purchased, as the gut needs to adapt to different feed and there is the risk of enterotoxemia with change of feed. There is also the risk of nitrate toxicity if you are feeding feed that is high in nitrate. Feed should be tested for nitrate prior to feeding to your stock. What nutrition do these cattle require? This is dependent on age and purpose eg weaners vs pregnant or lactating cows. It is preferable to always have some dry hay available when first putting new arrivals onto green pasture.

You can speak to our team about feed testing by calling 1300 795 299.

Biosecurity

Every property should have a Biosecurity Plan. Biosecurity relates to preventative measures designed to reduce the risk of transmission of infectious diseases, invasive pests or weeds. We need to prevent the spread between farms but also protect Australia from diseases and weeds that occur overseas.

Management practices will vary from property to property, depending on the size and nature of the livestock operation and the facilities available. Biosecurity for Australian livestock enterprises include Farm biosecurity plans and Industry biosecurity programs. Your farm biosecurity plan should outline what measures you have in place to reduce the risk of introducing an infectious disease, pest or weed onto your property. It should also include how you will reduce the risk of spreading an infectious disease within a property.

When you buy cattle, it isn’t just the cattle themselves that pose a biosecurity risk. It is the people that bring them (dirt, manure, contaminants on their hands, boots, clothing hair), the truck itself (dirt, manure, contaminants), any feed or manure and weeds or insects (such as ticks or mites) that may be inadvertently brought on the cattle or passed in their manure. Invasive plants can easily spread if brought in unintentionally.

To reduce the risk of introducing an infectious disease or weed when we buy in cattle, you should purchase stock from reputable producers and inspect stock before purchase if possible. Keep incoming stock separate from livestock already


AFRICAN HORSE SICKNESSAfrican Horse Sickness (AHS) is an arbovirus that affects horses, donkeys, mules and zebras. The virus is carried and transmitted by midges (Culicoides spp.). It is not spread directly between horses. It is often fatal and has high mortality rates of up to 95% in horses. It is endemic in parts of Africa, but is exotic to Australia.

Clinical signs of AHS include swelling and redness around the eyes and elsewhere on the face, frothing and discharge from nostrils, fever, slow and laboured breathing and coughing. There is no effective treatment for the disease. African Horse Sickness does not affect humans.

AHS was reported in Thailand for the first time in March 2020. It has been speculated that imported zebras may be responsible for this first outbreak in Asia. AHS has since been reported in Malaysia, 100 kms south of the Malay-Thai border on 2nd September 2020. It has never been detected in Australia.

As it is transmitted by biting Culicoides sp. midges that feed on horses, the spread of the virus can be very difficult to control where such midges are abundant. Culicoides sp. midges are endemic in parts of tropical Australia, which means that windborne spread of potential infected vectors from Asia into northern Australia represents a possible route of introduction to Australia. Early detection and diagnosis will be paramount in keeping AHS out of Australia.

BLUE GREEN ALGAE ALERT REMINDERLivestock owners are advised to regularly check the NSW Water website (/www.waternsw.com.au/supply/regional-nsw/alerts-and-updates) for reports of blue green algae levels that might pose a threat to livestock watering from affected bodies of water. Some species of blue green algae can produce toxins which are poisonous to livestock and people. Blue green algae can produce liver toxins, neurotoxins and toxins that cause dermatitis.

Algal blooms normally occur when water temperatures are warm, and become less likely during winter. In May 2020, however, when we might normally expect water temperatures not to favour algal blooms, Hunter Water advised that algal levels in the Williams River at Seaham weir were extremely high, prompting a Red Alert status due to the possible risk for livestock watered from that stretch of the river.

A NSW DPI factsheet on poisoning of livestock by blue green algae can be found at:

www.dpi.nsw.gov.au/__data/assets/pdf_file/0004/347089/Blue-green-algae-poisoning-of-livestock.pdf

Another NSW DPI factsheet describing control measures for blue green algae can be found at:

www.dpi.nsw.gov.au/__data/assets/pdf_file/0010/694243/farm-water-quality-and-treatment-algae.pdf

Farm water quality and treatment: Algae

4 NSW Department of Primary Industries, May 2017

Aeration can be achieved in a number of ways. The simplest method is to cascade the water into a

holding dam or tank. Alternatively, an aerator like the one pictured in Figure 2 can be used.

Chemical dosing to control algae

At the time of publication (2017), in NSW, only Coptrol Aquatic Algicide®, Cupricide Algicide® and

Cupricide 110 Algicide® are approved for the control of blue-green algae, green algae, diatoms and

flagellate algae. These products must be used in strict accordance with their label conditions and

directions. These products contain copper as mixed complexes and are registered for use in farm dams,

rice paddies and irrigation conveyance systems. They must not be used in rivers, streams, creeks,

wetlands, lakes or billabongs, and water treated with these products must not be allowed to spill into these

water bodies. Their conditions of use further prevent their application when birds are feeding on algae or

in water containing fish.As with all chemicals, read the instructions before use and wear the appropriate safety equipment.

Note: Do not treat drinking waters used by farm animals grazing on heliotrope or ragwort.

Alum and gypsum as a combined dose may be used to protect small dams from blue-green algae, as they

remove phosphorus from the water. Gypsum appears to be less effective if pH values in the water are

below 10.

Dosing procedure (farm dams only)

Add the granules of alum crystals to the water and mix well. You could perhaps use a boat with an

outboard motor to mix in the crystals. Let the water stand for a few hours, and add the gypsum

granules. Let the water stand for at least 24 hours, or until it clears. If it does not clear within two

days, add 25 to 50 per cent of the recommended dosage of alum and gypsum to promote settling.

After dosing, check the pH of the water with a swimming pool testing kit. The pH should be in the

range 6–9. If it is not, allow the water to stand two days and check again.

Dosing with alum and gypsum is only appropriate for farm dams, and must not be applied to natural

waterways. Ideally dosing should be carried out before summer, and certainly before a bloom has

developed. The recommended dose for a farm dam is 50 kilograms of alum and 50 kilograms of gypsum

for each megalitre of water. Because of variations in water quality and algae, it is advisable to conduct a

preliminary trial in a “44-gallon drum” (200 litre container) to establish the correct dosage.

Figure 2. An aerator will help keep algae levels low

Farm water quality and treatment: Algae

3 NSW Department of Primary Industries, May 2017

Dolichospermum and Microcystis are the most common types of freshwater blue-green algae causing

blooms. Dolichospermum generally grows in rivers and lakes and Microcystis is often found in lakes and

reservoirs.Blooms may be seen as a green colouration in the water or as a surface scum. Scums are often green or

blue-green and vary in consistency from paint-like slicks to small green floating dots.Toxic blue-green algae can produce three different forms of toxins: 1. Hepatotoxins attack the liver and other internal organs. They can cause gastroenteritis, nausea,

vomiting and muscle weakness.2. Neurotoxins affect neuromuscular performance and can lead to paralysis and respiratory arrest. 3. Lipopolysaccharides are skin irritants that can cause dermatitis and conjunctivitis. They may also

cause stomach cramps, nausea and fever if consumed.If you suspect blue-green algae are in your water, contact Local Land Services or the NSW DPI Water for

advice. Confirming the species present, cell count or biovolume per volume of water and, if required,

presence of toxins, are key steps to determine the risk to water quality and associated uses. In the interim,

do not use the water for stock watering or domestic or recreational use, and do not allow stock to graze

algal mats.Effects on irrigation waterRisks must be assessed if considering use of water contaminated by blue-green algae for irrigation.

Human and animal health may be threatened if contaminated water is applied directly to crops and

pastures as many toxins are very slow to break down and may be incorporated into vegetative matter and

then ingested. Do not use water that has blue-green algae in it directly on plants being grown for human

consumption. This is particularly so for spray-irrigated salad and leafy vegetables, as dried algal cells on

the leaves can remain toxic for several months. As a rule, all fresh produce such as fruit and vegetables

should be washed thoroughly with clean uncontaminated water before eating, regardless of water source

and conditions.Potential for BGA toxins to accumulate in plant tissues, soil and groundwater at the field-scale requires

investigation. Toxins may potentially accumulate in some soil types and threaten groundwater quality.

Effects on livestockLivestock can die from drinking contaminated water. The toxins can cause scouring, red urine, liver

damage and sudden death in cattle and sheep. Surviving animals show photosensitivity, which is a form of

sunburn restricted to white areas of cattle and the nose and ears of sheep. This may affect feeding and

result in cows refusing to suckle their young. Milk production may decrease in dairy cows. Scouring occurs

with poultry, resulting in reduced egg production. Deaths have also been recorded in bees and dogs, and

toxic algae have been implicated in the death of wildlife.Effects on domestic usageYou should not cook, bathe, wash your clothes or swim in water affected by BGA. Skin contact through

showering or swimming may result in skin irritations, swollen lips, sore throats, eye and ear irritations,

rashes and hay fever symptoms. Drinking affected water may result in diarrhoea, nausea, vomiting and

muscle weakness. Boiling the water will not reduce the effect of blue-green algae toxins. See your local

doctor immediately if you experience symptoms you think result from blue-green algae in your water.

TreatmentIf an algal bloom is suspected, you should find an alternative supply of water for domestic, stock and

irrigation use until the algae is identified. The best way to manage algal blooms is to prevent them from

happening. A key long-term strategy is to improve nutrient management and erosion control on your farm.

This will help control blue-green algae in your farm dam and assist with management of blue-green algae

in rivers and creeks.Algae will not grow in total darkness, so cover the top of domestic storage tanks to exclude all light. Do not

use translucent fibreglass tanks.Artificial aeration can help mix up the water and add oxygen in farm dams. This may help control

accumulations of soluble iron, ammonia and hydrogen sulfide, as well as help to control algal blooms.

Farm water quali

ty and treatment

: Algae

May 2017 Prime

fact 1506 Third

edition

Agriculture NSW

Water Unit

Farm water com

es from a numb

er of different so

urces and so its

quality varies. W

ater sources inc

lude

dams, bores, we

lls, rivers, town

water, channels

and recycled wa

ter.

Water from vario

us sources may

be of an unsuita

ble quality for its

intended use fo

r irrigation, stock

,

household or oth

er farm activities

.

It is important to

identify and cor

rect water qualit

y problems that

may affect on-fa

rm use and pro

ductivity.

Knowing your w

ater quality

If you have any d

oubt about the

quality of water y

ou intend to use

for irrigation, st

ock or domestic

purposes, get it

tested by an acc

redited laborato

ry. You should h

ave your water

tested before yo

u plan to

irrigate potentiall

y sensitive crop

s, and at various

other times, as

required.

Your Local Land

Services adviso

ry officer can as

sist withinforma

tion which is rel

evant to your fa

rm

system and opti

ons to manage s

pecific problems

in your water su

pplies.

Knowing your wa

ter quality allow

s you to plan for

water treatmen

ts to avoid proble

ms such as poor

plant

growth, blocked

irrigation or sto

ck watering pipe

s, staining and

other undesirabl

e effects of poor

water

quality.

Water quality is

sues

Problems with w

ater quality may

be chemical (for

example, acidic

or alkaline wate

r or concentratio

ns of

certain elements

) or physical (fo

r example, plant

growth such as

algae). Some p

roblems may be

more

obvious than ot

hers, and some

may require mo

re extensive trea

tment.

Water quality ca

n affect plants, s

oils, livestock, ir

rigation equipme

nt, domestic us

e and general fa

rm

activities.

This Primefact d

iscusses the iss

ues related to th

e treatment and

control of algae.

Algae

Algae are small

forms of plant li

fe that exist in a

wide range of h

abitats. They ar

e commonly tho

ught of as

aquatic organism

s but many are t

errestrial or live

in association w

ith other organis

ms like fungi an

d

animals. They la

ck roots, stems

and leaves, but,

like other plants,

have chlorophy

ll as their prima

ry

photosynthetic p

igment.

Algae occur nat

urally in both fre

sh and brackish

water sources. L

ike all plant life,

algae respond to

sunlight

and fertilisers, a

nd excessive al

gal growth will o

ccur when envir

onmental condi

tions are right. F

or

example, excess

ive algal growth

(Figure 1) can

occur when nutr

ients, particularly

phosphorus an

d

nitrogen, pollute

the water. As li

ttle as 0.01 mg/

L phosphate in f

reshwater lakes

and streams stim

ulates

the growth of alg

ae and other aq

uatic life that ma

y clog irrigation

systems and ma

ke water unpala

table to

stock.

As well as respo

nding to excess

ive nutrients, alg

al blooms are m

ost likely to occ

ur when:

• the water is

calm

• the water te

mperature is wa

rm (above 20 °C

)

https://www.waternsw.com.au/supply/regional-nsw/alerts-and-updateshttps://www.waternsw.com.au/supply/regional-nsw/alerts-and-updateshttps://www.dpi.nsw.gov.au/__data/assets/pdf_file/0004/347089/Blue-green-algae-poisoning-of-livestock.pdfhttps://www.dpi.nsw.gov.au/__data/assets/pdf_file/0004/347089/Blue-green-algae-poisoning-of-livestock.pdfhttps://www.dpi.nsw.gov.au/__data/assets/pdf_file/0010/694243/farm-water-quality-and-treatment-algae.pdfhttps://www.dpi.nsw.gov.au/__data/assets/pdf_file/0010/694243/farm-water-quality-and-treatment-algae.pdf


BLUE GREEN ALGAE PROJECTBlue green algae (also known as cyanobacteria or cyanophytes) are a common issue in farm dams and other waterways. Blue green algae can release toxins into the water which can have a wide variety of adverse health effects on man and animal. Depending on the species of algae, these adverse effects can vary from skin irritation in people swimming in affected water through to sudden death of livestock that consume affected water.

However, not all species of Blue green algae produce toxins, and even the toxic species of algae do not always release toxins. This makes it difficult to assess the risk to livestock presented by an algal bloom in a farm dam, as toxin may be absent one day, but present the next. For this reason, once a toxic species of algae is identified from a water sample submitted to a laboratory, the advice is to treat the water as suspect in case toxin is suddenly elaborated.

An unfortunate complicating factor is that treatment of farm dams with chemicals to kill algal blooms can prompt the release of toxin, meaning that the act of attempting to reduce the risk to livestock might unintentionally increase it temporarily. NSW DPI has produced a number of algae information sheets available online, which can be found at:

www.dpi.nsw.gov.au/agriculture/water/quality/pubs-and-info/blue-green-algae

Because algal blooms occur more commonly in warm water loaded with nutrients, the drought we experienced over the last few years created suitable conditions for algal blooms. Because of the potential threat to livestock, Hunter LLS has offered a water testing service to identify algae collected from farm dams. That service will continue over the 2020-21 summer.

Because the safety of such water can be of immediate importance in situations where a sudden algal bloom may make the only source of stock water in a paddock or on a small property potentially poisonous, Hunter LLS plans to undertake a project over the 2020-21 summer whereby on-farm testing kits will be trialled in affected farm dams to identify algal species and also the presence of toxin. We would also like to trial the effectiveness of various treatments and their claimed freedom from the effect of causing toxin release.

Hunter farmers wishing to participate in such a trial should contact their local District Veterinarian. The contact numbers for all Hunter LLS District Vets can be found at the end of this newsletter.

Livestock owners are advised to regularly check the NSW Water website (www.waternsw.com.au/supply/regional-nsw/alerts-and-updates) for reports of blue green algae levels that might pose a threat to livestock watering from affected bodies of water such as local rivers and reservoirs.

Image: NSW DPI Primefact 1506: farm water quality and treatment: Algae

https://www.dpi.nsw.gov.au/agriculture/water/quality/pubs-and-info/blue-green-algaehttps://www.dpi.nsw.gov.au/agriculture/water/quality/pubs-and-info/blue-green-algaehttps://www.waternsw.com.au/supply/regional-nsw/alerts-and-updateshttps://www.waternsw.com.au/supply/regional-nsw/alerts-and-updates


HELPING PRODUCERS RECOVER FROM BUSHFIREWas your property affected by fires in November and December 2019?

Do you have livestock health and production concerns following the fires? Maybe stock have strayed onto or off your property and you are worried about disease introductions. Maybe fence damage has limited your access to paddocks creating a parasite burden problem in livestock? Maybe water quality in farm dams is still affected by ash or other contaminates. These and other similar issues are the focus of the HLLS Bushfire Recovery Program.

Please call your District Veterinarian or Biosecurity Ranger to discuss any issues your livestock or farm is facing We may be able to help with strategic testing to help your farm and your livestock

We are keen to help.

BOVINE EPHEMERAL FEVER (BEF) VACCINATION CONSIDERATIONS We are often asked to provide advice regarding BEF vaccination of cattle. In particular, producers ponder if they should vaccinate cattle following a season with strong BEF transmission as we had in March to May of 2020.

There is the belief that virus transmission will be complete within the herd and that all cattle will be infected and then immune for life.

However, the LLS/DPI mosquito/midge borne disease surveillance data (National Arbovirus Monitoring Program) paints a different picture and can help answer this question. As can a consideration of the action of the vaccine and duration of immunity of natural infection.

Another common question is “is it necessary to continue to provide BEF booster injections year after year”? Producers wonder if they vaccinate their herd, will the vaccine prevent cattle from generating longer lasting natural immunity, if they are then naturally infected. All great questions. Please read on for answers to these and many more.

When is the best time to vaccinate?

Late winter /spring is the ideal time to consider your cattle vaccination plans for Bovine Ephemeral Fever Virus. Initial vaccination requires two injections from two weeks to six months apart. It is recommended to provide the initial primer dose in late winter (August - September) and the second vaccination in early summer (Nov-Dec), so that stock are protected when the virus arrives in our region. This is often in late summer, but sometimes can catch us by surprise with an early season start.

The benefit of this approach is that if the BEF season looks like it will arrive early then the second vaccine or annual booster can be quickly administered and within 7-10 days cattle should have solid immunity.

Annual boosters should ideally be given 8-10 weeks before virus transmission.

Please also be aware that vaccine availability (vaccines are available from your private veterinarian) can be in short supply when the season is imminent. Speak with your private vet early to secure supply.

In an unvaccinated herd, what level of BEF infection and antibody protection can I expect throughout my herd after seasonal transmission?

Hunter LLS, in partnership with DPI, monitors four sentinel herds on a monthly basis to assess the seasonal distribution of several economically important mosquito and midge borne


arboviruses; Bluetongue, Akabane and Bovine Ephemeral Fever Virus. These viruses are transmitted only when vectors are in sufficient density. The main vector of BEF virus in Australia is generally considered to be the mosquito Culex annulirostris. C. annulirostris has different ecological thresholds from the main vector of both Bluetongue and Akabane the midge; Culicoides brevitarsis. BEF generally has a wider distribution than Akabane and Bluetongue virus.

Ten very young beasts (not previously exposed to arboviruses) are blood sampled monthly from October to July, to identify virus distribution and infection prevalence as an indication of wider herd/regional exposure. Reports from this program are available at www.animalhealthaustralia.com.au/what-we-do/disease-surveillance/national-arbovirus-monitoring-program/

rates (8/10) animals infected but Paterson did not record any infection and only minor levels of infection (3/10 animals) were recorded at Taree. This highlights the vagaries of mosquito distribution carrying the virus. Sometimes it tracks down the coast and then inland, but other years it appears inland first and heads across to the Upper Hunter as well as tracking down the coast as in 2020.

There is also the theory – backed by many years of regional experience – that the Hunter has a microclimate that may be able to support overwintering of the virus and mosquitos. This is borne out by surveillance data that showed that BEF was detected at Wingham in December 2016, prior to anywhere else in the state. There have been other isolated examples of this in the previous 20 years, elsewhere in the Hunter.

Practically this means when buying cattle from other areas of the Hunter one cannot assume they will have had the same BEF exposure or protection as your own herd.

Diagram 5: Results from BEF sampling of 20 mature dairy cattle in September 2020 shows that cumulative infection levels reached 70% positive with 30% still negative. This compares with results of 50% of young heifers achieving infection in one year.

This highlights cumulative infection and antibody protection generated through various age cohorts. Still does not cause 100% of the herd to be immune to BEF.

Can I mix, store and then use the vaccine on additional days.

No. Mix and use on the same day as per label directions. When mixed the diluent inactivates the BEF virus. Antibody protection and challenge studies show that delayed use reduces antibody levels and hence protection.

Will BEF Vaccination prevent my cattle from achieving long lasting antibody protection from natural infection?

The vaccine does not produce sterilising immunity and vaccinated cattle that receive natural exposure to the virus will have the same solid long-lasting immunity as cattle that survive natural exposure.

Is natural infection life long?

Natural infection is generally regarded as long lasting, but probably not lifelong. As cattle age, particularly as they enter the geriatric age bracket (10 years plus), they become

In addition to this data, sampling of 20 adult dairy cows, undertaken this month, from a Lower Hunter herd that had recorded BEF infection in three of the last five years, found 14 animals were BEF positive and 6 BEF negative. This result surprised us as well considering this herd, reported many down and affected cattle in April/May of this year (diagram 5) and BEF was seasonal transmitted in 2016, 2018 and 2020.

This data highlights that natural infection throughout a herd is unlikely to be compete, even in the face of multiple infection opportunities over several years, and if you are relying on 100% natural infection to provide antibody protection in the absence of vaccination, then please think again.

BEF distribution can be very patchy in a region.

The other interesting finding is the variability in BEF transmission between district herds in the Hunter. In some years (2017), Upper Hunter herds had relatively solid infection

Diagram 1 Diagram 2

Diagram 3 Diagram 4

Diagram 1-4, graphs antibody results of ten animals sampled in each of the four sentinel herds; Taree, Paterson, Singleton and Scone during 2016, 2017, 2018 and 2020. Due to the drought BEF did not circulate in 2019 in the Hunter. Infection rates across the ten sampled animals did not achieve anywhere near 100%.

https://www.animalhealthaustralia.com.au/what-we-do/disease-surveillance/national-arbovirus-monitoring-program/https://www.animalhealthaustralia.com.au/what-we-do/disease-surveillance/national-arbovirus-monitoring-program/https://www.animalhealthaustralia.com.au/what-we-do/disease-surveillance/national-arbovirus-monitoring-program/


UNUSUAL PNEUMONIA AND EMPHYSEMA IN BEF INFECTED CATTLEProducers are asked to be on the lookout for any unusual signs of Bovine Ephemeral Fever this BEF season and report these to your District or Private Veterinarian. In particular, we are interested in cattle that present with respiratory distress and/or pneumonias, whilst Three-Day Sickness is circulating. Three day often circulates in late summer on the coast.

As reported in the Autumn edition of Hunter Local Land Services Livestock Health News, District and Private Veterinarians in the Mid Coast and Lower Hunter region worked together to diagnose an unusual manifestation of Three Day Sickness in early April 2020.

Several unusual Bovine Ephemeral Fever cases were diagnosed over a period of 10 days on four dairy farms. These animals presented primarily with grunting and respiratory distress (head, neck extended) and subcutaneous emphysema (gas under the skin of the backline). This occurred concurrently with other animals in the herds showing the more classic signs of BEF such as shifting lameness, lethargy, salivation and nasal discharge, fever and recumbency. A number of cattle died from this unusual BEF presentation until early case identification and treatment was implemented.

less efficient at mounting an immune response to natural challenge. Thus, if you are relying on immunity from natural infection to protect your older cattle (ie older breeders, milkers, bulls) they might benefit from BEF vaccination to boost antibody protection.

Should I vaccinate my herd against BEF? Which animals are a priority?

The decision to vaccinate stock against Bovine Ephemeral Fever (BEF) virus often comes down to a consideration of both animal welfare and potential production losses from the fever and lameness, and the resulting condition, pregnancy and lactation losses. Occasional cattle deaths either due to primary BEF infection or secondary effects from the virus and sustained recumbency can also occur. The extra workload created by having to nurse down cattle is a major consideration for dairy and beef herds and absentee cattle owners. In the latter, it becomes a welfare issue not to vaccinate stock. During BEF season stock must be inspected daily for any down cattle that may require water, shade and veterinary attention.

In summary, we suggest developing a program that suits your situation (dairy, beef, absentee or off farm worker) and approach to risk.

The BEF Vaccination Hierarchy

The general recommendation is to consider a vaccination hierarchy. Vaccinate the most important stock and work your way through the groups as your resources and situation dictates. Many producers routinely vaccinate all cattle over six months of age others have a more selective approach.

As a priority vaccinate;

1. Bulls, non-immune pregnant and lactating cows, well-conditioned cattle and cattle introduced from non BEF endemic areas.

2. Breeders and milkers in the first and second year of production, ie maiden heifers and first and second calvers.

3. Very old cows ie older than 10 years.

4. Calves over six months of age are the final group for consideration. Generally, this age bracket copes the best with the disease. If you opt not to vaccinate this group please ensure you have a plan to manage any affected cases that require assistance.

Please also make yourself aware of the district’s history of BEF infection as a transmission hiatus of a couple of years’ can dramatically change the situation. As discussed, elsewhere in this edition, BEF is not always a minimal disease and at times can cause considerable illness and death in some animals as outlined in the BEF emphysema cases found in 2020 in the Hunter.

Please see earlier article on how to treat down and lame cattle suffering from BEF www.lls.nsw.gov.au/__data/assets/pdf_file/0017/1214711/animal-newsletter-autumn-2020.pdf

https://www.lls.nsw.gov.au/__data/assets/pdf_file/0017/1214711/animal-newsletter-autumn-2020.pdfhttps://www.lls.nsw.gov.au/__data/assets/pdf_file/0017/1214711/animal-newsletter-autumn-2020.pdf


Testing by Hunter Local Land Services confirmed that the affected animals were positive for BEF and post mortem investigations found gas under the skin and internally and an interstitial pneumonia and pulmonary emphysema, with one case of ruminal bloat. Whilst ruminal bloat/ruminal stasis associated with BEF is relatively well known, BEF associated emphysemas/pneumonias are less recognised. In all cases, of this unusual BEF, the cattle were relatively young ie less than three years old.

Cases of BEF occur in the mid coast and Lower Hunter area in most years. However, due to drought conditions the region mostly skipped virus distribution in 2018 and 2019 with the last recorded period of transmission (prior to March 2020) being in summer /autumn 2017. Thus most locally born cattle

A N I M A L H E A LT H N E W S w w w. l ls . ns w.gov. au /re gions/ hunter | 130 0 795 29 9

HERE’S HOW TO CONTACT YOUR DISTRICT VET:

Jim Kerr – Tocal 0439 185 275

Kylie Greentree – Maitland 0428 498 687

Kristi Arnot – Singleton 0409 758 823

Lyndell Stone – Wingham 0429 532 855

Jane Bennett – Scone 0427 322 311

FOR MORE INFORMATION ABOUT HUNTER LOCAL LAND SERVICES:

1300 795 299

@ [email protected] www.lls.nsw.gov.au/regions/hunter

www.facebook.com.HunterLLS

Hunter Local Land Services816 Tocal Road (private Bag 2010)Paterson, NSW 2421 Australia

0001

/AN

0620

At this point, the local DV was contacted and the bull was euthanised due to poor prognosis/welfare grounds and a thorough post-mortem undertaken.

A large abscess containing the bacteria Trueperella Pyogenes was found tracking through the loin muscles to the spinal cord. It had compressed the spinal cord at the first lumbar vertebrae, hence the hind limb paralysis. The bull’s spleen was free of the BEF virus. The bull’s true stomach was found to have some ulcerations.

Abscesses can occur from injury such as fighting and the thoracic/lumbar junction is structurally weak compared to other parts of the spine. Intramuscular injections can also be a source of bacterial infection as can ulcerations in the intestines that might form a portal of entry for bacteria into the blood stream.

The bacterial abscess had tracked through the lumbar muscles to impinge on the spinal cord causing the hind limb issues.

This case highlights the importance of investigating animals exhibiting neurological signs, but also seeking early veterinary attention for illness of more than a couple of days duration. It is also a salient reminder of the stoicism of cattle and that by the time they show signs of illness they are often critically ill.

Thanks to this and all producers who contact their private or government District Vet to have unusual or multiple illnesses investigated. Through these actions we can continue to demonstrate that Australia is free from exotic diseases and maintain our enviable international market access.

Abscess

DISEASE INVESTIGATION - A “dog sitting” Bull

In April, a Hunter LLS District Veterinarian (DV) attended a bull with an unusual and progressive hindlimb weakness. The producer contacted the DV for advice on the Bull’s welfare.

The producer suspected complications associated with BEF. However, it is important to ensure this type of neurological condition is not associated with an exotic disease such as Bovine Spongiform Encephalopathy (BSE) commonly known as Mad Cow Disease.

The bull’s illness coincided with the arrival of Bovine Ephemeral Fever in the region. Due to the bull’s young age (< 3 years) he most likely had not previously been exposed to BEF as the region had experienced a BEF transmission hiatus of several years.

Many farms had multiple young cattle down or affected by BEF and the producer noted that the Bull’s clinical signs mimicked those of its peers. The producer had also done his research and identified that in a small percentage (1%) of BEF cases the virus lodges in the spinal cord and cattle can become recumbent. Thus, was rightly suspicious of this course of events. Hunter LLS DVs were also tracking some other unusual BEF related illnesses and deaths and collectively these were all worthy considerations requiring investigation.

The Bull, whilst vaccinated against BEF in December 2019, was showing similar signs of lameness, seeking shade, a swollen knee joint and recumbency. It is noted that BEF vaccinated cattle can still become infected with the virus but the course of the disease is shorter and less severe.

However, instead of improving after a short illness, the Bull’s mobility continued to deteriorate, even though he continued to eat and drink. Administration of a short course of anti-inflammatory medication (important for BEF cases) and antibiotics provided some short-term improvement. But over the course of several weeks the bull became increasingly miserable, more frequently recumbent and tellingly, for a spinal lesion in the thoracic to lumbar region (T3-L2), began to “dog sit”. This is where a ruminant weight bears on extended front limbs, but rests/sits on flexed hind limbs.

http://www.lls.nsw.gov.au/regions/hunter

_GoBack_GoBack_GoBack_Hlk44960489_GoBack_GoBack_GoBack_GoBack_GoBack_Hlk44403906_Hlk44402277_Hlk47528085_GoBackCALF SCOURS IN BEEF HERDSCALF SCOURS PREVENTION PLANDID YOU BUY QLD HAY DURING THE DROUGHT?TICKS CAN ALSO AFFECT PEOPLETRANSPORTED STOCK STATEMENTS FOR HORSE MOVEMENTS NOW AVAILABLE ONLINESALMONELLA ENTERITIDIS UPDATEAVIAN INFLUENZA INCURSION IN VICTORIA CHICKEN BIOSECURITY (NSW DPI) AVIAN INFLUENZA EXCLUSION IN THE HUNTER VACCINATE NOW TO PROTECT LIVESTOCK FROM ANTHRAXBUYING NEW STOCK: QUARANTINE AND BIOSECURITYAFRICAN HORSE SICKNESSBLUE GREEN ALGAE PROJECTHELPING PRODUCERS RECOVER FROM BUSHFIREBOVINE EPHEMERAL FEVER (BEF) VACCINATION CONSIDERATIONS UNUSUAL PNEUMONIA AND EMPHYSEMA IN BEF INFECTED CATTLEBLUETONGUE VIRUS ZONE EXTENDED DISEASE INVESTIGATION - A “dog sitting” Bull

Animal health Hunter - lls.nsw.gov.au · Animal health advice for producers in theHunter Contents...

Documents

Transcript of Animal health Hunter - lls.nsw.gov.au · Animal health advice for producers in theHunter Contents...