What does a Warning to Sheep Graziers mean?

It is the time of the year when plenty of lambs will be hitting the ground, and you might see the BOM put out a Warning to Sheep Graziers.

But what does that mean, really?

A Warning to Sheep Graziers is a winter weather warning. These are common in southern parts of Australia, and in extreme cases issued for Queensland. They are issued when cold, wet and windy weather (together) is expected. This is the weather than can cause hypothermia in sheep.

High rainfall and high winds combined with temperatures below normal will cause mortalities in young animals,  especially lambs and pregnant ewes without shelter. The impact of the cold weather will depend on its duration, rainfall, wind speed and temperature.

Rainfall causes heat loss in two ways. First, any water evaporated from the skin will cool the body in the same way as sweat evaporation. Second, rain falling on the sheep, lodging briefly in the fleece, and finally dripping off will remove warmth from the skin.

Animals most affected by hypothermia are:

• new lambs

• late stage pregnant ewes

• animals in poor condition

If you have non shedding sheep, then freshly shorn sheep are also susceptible.

So, you have been warned. What now?

It is important that lambing ewes and young lambs are in paddocks that contain the best shelter or protection from the weather.

That can be:

• constructed wind breaks such as corrugated iron along fences or hay bales placed in the paddock

• natural undulating paddocks with hollows and gullies trees, other vegetation or artificial structures, so they can get somewhere they are blocked from the wind. (This can improve the survival of newborn lambs in the event of cold snap conditions occurring within the first two weeks of lambing)

• sheds (open on one side) erected in paddocks can provide protection from wind

• forestry blocks can be used as emergency shelter for large numbers of stock, and can provide protection during sudden storms.