THE extreme shift in weather conditions from mild to scorching temperatures has caused a spike in summer pneumonia in sheep, as veterinarians warn producers of the consequences of nutrition loss.
Last month marked the eighth-wettest January on record for the nation as a whole, creating problems with the germination of toxic weeds and caused stubble quality to deteriorate.
January rainfall was the third-highest on record for Western Australia and the ninth-highest on record for South Australia, according to the Bureau of Meteorology.
The summer rainfall across the country followed by heatwaves has resulted in an increase in weaner lamb losses from summer pneumonia, according to Livestock Logic veterinarian David Rendell, Hamilton, Vic.
“A lot of the stock have done well up until now but have lost weight in the past week or so,” Dr Rendell said.
“We’ve had several cases of harmful to fatal summer pneumonia with outbreaks of up to five per cent of stock lost.”
With cases reported in WA, SA, Victoria and NSW, Dr Rendell warned symptoms of summer pneumonia included coughing and nasal discharge.
Dr Rendell said weaner lambs’ whose growth rates were below 30 grams a day and condition was in decline were at risk.
“Summer pneumonia is mainly impacting 2016-drop lambs that have not been on stubble or grain fed long enough, been on poor quality pasture and are losing condition,” he said.
“We had an outbreak in weaner stud-bred rams that were in good condition so it was assumed they could afford to cruise for a while.
“You can get loses with pneumonia with well grown weaners if they have a period of declining condition.”
Dr Rendell said producers with stock on dry feed should be supplement feeding.
“Because there has been so much rain, pasture has grown high and the dry feed quality has been depleted,” he said.
“Pasture grew rapidly through the spring and become rank so as it’s dried off it is high in quantity but low in quality – hay testing has reflected this.
“Since drying off, the regular rainfall leaches out the nutrients and sugars in the dry feed so it deteriorates quicker.”
He said the rain may germinate toxic weeds, as well as cause phalaris and annual rye grass toxicity (ARGT).
While monitoring at-risk paddocks would be essential, Dr Rendell advised the prompt removal affected stock to alternative paddocks.
“Based on previous years, we expect this year to be bad,” he said.
“Ryegrass staggers is not really treatable but it is reversible if stock are moved off the paddock.”
Signs of sheep affected by ARGT include shaking, a clumsy gait, jaw champing, throat paralysis and dullness, followed by lying down and convulsions.
Conditions can be made worse by stress or moving the animals, where stock can suddenly collapse or have a seizure.
In response to nutrition warnings, Koonik Dohne co-principal Fiona Cameron, Nurcoung, Vic said flock ewes were grazing stubble to sustain them at condition score three during joining and would be introduced to grain in the coming weeks.
“The ‘green pick’ looks good but what you see is not necessarily what is there in nutritional value,” she said.
“It is easier to keep sheep in good condition than getting them back into condition which can be hard.”
While the recent rainfall had stimulated germination from spilt grain from stubbles, Ms Cameron said the summer plants had inadequate nutrition for joined ewes’ energy requirements.
“As the crops have been harvested I’ve been gradually introduced sheep slowly into each paddock, increasing the length of time sheep spent on the stubble,” she said.
However the high rainfall received in the past month has impacted the nutritional value of the pasture, which Ms Cameron said would see the Dohne flock supplementary fed with barley-based lick feeders.