WESTERN Australian sheep producers have been warned to look out for signs of nutritional diseases among lambing ewes at the break of the season.

The Department of Primary Industries and Regional Development has recently received many reports of the diseases from across the wheatbelt and Great Southern regions.

The department said lambing ewes are particularly vulnerable to pregnancy toxaemia and hypocalcaemia at this time of the year, when nutritional needs are increasing as cold and wet conditions set in.

DPIRD field veterinary officer Rod Thompson encouraged producers to maintain adequate stock nutrition, minimise mustering, yard off feed and monitor flocks regularly for symptoms.

He said it was important for producers to take action to treat affected sheep promptly to reduce deaths, which can occur within days of symptoms first appearing.

“Pregnancy toxaemia, also known as twin lamb disease, occurs when low glucose levels damage the brain, resulting in dehydration and kidney failure.

“Watch for ewes that have separated from the mob, become drowsy or comatose, are not eating, have tremors, blindness or lying on their side,” Dr Thompson said.

“Hypocalcaemia, or milk fever, is a calcium deficiency that prevents muscles from contracting, including muscles in the heart, gut, legs and those involved in the lambing process.

“Symptoms can set in rapidly, such as a stiff uncoordinated gait, muscle trembling, weakness and sheep sitting on their brisket and unable to get up.”

WA producers have been urged to contact a private or DPIRD veterinarian immediately if they see signs of the diseases for correct diagnosis and treatment advice.

An investigation by a private veterinarian may be eligible for a subsidy under DPIRD’s Significant Disease Investigation Program(link is external).

Dr Thompson said both diseases could be prevented by maintaining good nutrition and reducing stress factors, such as mustering and yarding off feed overnight.

“Feed is still short in many areas and many producers have been confinement feeding pregnant ewes, however, lambing in confinement is not recommended and ewes should be back in the paddock two to three weeks before lambing,” he said.

Supplementary feeding pregnant ewes will need to continue in the paddock until at least 800 kilograms of dry matter per hectare of Feed on Offer (FOO) is available, while lactating ewes will need 1500-2000kg DM/ha.

DPIRD recommends deferring grazing for about five weeks after plant emergence or until there is at least 500-800kg DM/ha FOO to help pastures establish and reach adequate FOO levels, while also improving ongoing pasture growth.

Deferred grazing can include feeding ewes in sacrificial paddocks with low erosion risk or grazing early germinated crops, plus the use of perennials or fodder shrubs.

For more information on livestock diseases, deferred grazing, supplementary feeding as well as a wealth of other livestock management advice, visit the Season 2024 webpages(link is external).