AgMemo - Livestock news, August 2018

Page last updated: Thursday, 16 August 2018 - 4:20pm

Please note: This content may be out of date and is currently under review.

Livestock diseases to watch for in winter and spring

Sheep in paddock
Be on the lookout for selenium deficiency in lambs and calves, listeriosis and salmonellosis in sheep.

As we near the end of winter and move into spring, there are a number of livestock diseases producers are being asked to keep a lookout for.

The Department of Primary Industries and Regional Development (DPIRD) recommends calling a vet to investigate ill livestock as this helps protect our livestock and livestock product markets.

Livestock diseases to look for include:

Selenium deficiency in lambs and calves

Selenium deficiency occurs in young animals as they have an increased demand for the trace element during growth and have not accumulated the body stores of adult animals.

Animals are typically grazing lush, rapidly growing pasture or legume-dominant pasture in the higher rainfall areas of the southwest coastal regions.

Paddocks heavily fertilised with sulphur-containing or superphosphate applications may also predispose animals to deficiency.

Key signs include poor growth, stiff gait, arched back, apparent lameness, reluctance to move and sudden death.

Animals that show visible signs of deficiency can be supplemented in the short term with a selenium injection or drench but producers should read dosing instructions carefully as too much selenium can be fatal in stock.

Read more about selenium deficiency in sheep and cattle and how to prevent animals becoming deficient in the long term on the department’s website.

Listeriosis

Listeriosis is caused by the zoonotic bacteria Listeria monocytogenes.

Sources of infection include contaminated soil, spoiled feed and where apparently healthy animals (including rodents) have shed the bacteria in their faeces.

Listeriosis is primarily reported in winter and spring when heavy rainfall is more likely to spoil silage.

Livestock then consume contaminated feed material and can be infected when rough feed causes abrasions in the mouth.

Key signs include neurological symptoms, unwillingness to rise and death. Listeriosis may also cause abortions five to six weeks before lambing, stillbirths or newborn lamb deaths.

If feeding silage, ensure it has been properly prepared and inspected and ensure any leftover feed is cleared away.

Salmonellosis in sheep

The most common form of Salmonella in WA is S. Typhimurium.

Producers should always observe proper hygiene practices when handling animals as Salmonella is zoonotic and can be transmitted to people.

Salmonellosis is more commonly observed in winter and spring, but can occur at any time of year.

Outbreaks are often preceded by periods of stress, high stocking density and wet and cold weather.

Sources of Salmonella include carrier sheep (may comprise 2% of the flock), wild birds, rodents and the environment.

Key signs include severe, foul-smelling diarrhoea, fever, dehydration and straining to defaecate.

Australia’s access to markets for livestock and livestock products depends on evidence from our surveillance systems that we are free of reportable and trade-sensitive livestock diseases.

To gather this proof of freedom, the DPIRD investigates cases where livestock show signs similar to reportable or trade-sensitive diseases.

The WA livestock disease outlook monthly e-newsletter for producers (WALDO) is collated from information collected by DPIRD and private veterinarians as part of proving Australia’s freedom from those diseases.

For more information on recent livestock disease cases in Western Australia and diseases likely to occur in the next month, subscribe to DPIRD’s WALDO by visiting the DPIRD website or email .