Weaning key to dwindling flock, sustainability
Please note - This news release has now been archived and may contain outdated information.
With Australia’s sheep flock at its lowest level for over 50 years, national weaning percentages need to be lifted by 10 to 15 per cent for the flock to be even close to sustainable.
The implications of this reduction for the sheep flock are enormous, as mutton available for slaughter is predicted to decline to about 8.5 million head, compared with a long term average of 16 million head.
Lambs available for slaughter should increase in 2004/2005 until a decline in ewe numbers starts to decrease supply in 2005/2006.
Replacement ewe prices should remain high due to the shortage of ewes nationally which has a significant impact on the gross margins of lamb enterprises.
The percentage of Merino ewes joined to meat rams to produce slaughter lambs has increased from 15 per cent in 1990 to 47 per cent in 2003, with the result that more than two thirds of lambs slaughtered are bred from Merino ewes.
At the same time the number of Merino ewes has dropped from 60 million in 1990 to 45 million in 2002 with the decline continuing.
Merino breeders can now use a simple flock structure model to look at the impact of the percentage of ewes joined to meat rams on the number of replacement ewes generated.
The model was developed by Matthew Kelly and Andrew Swan from CSIRO Livestock Industries in Armidale, working collaboratively with the Australian Sheep Cooperative Research Centre.
Used on a flock of 4500 ewes, the model showed there was a deficit of 478 hogget ewes at 60 per cent weaning due to drought, and 47 per cent of Merino ewes joined to meat rams with no culling of ewes from the flock.
The national average lambing percentage in Merinos is estimated at 75 per cent in most years.
It may be an oversimplification to translate the individual flock to the national flock of 45 million Merino ewes; however this would indicate the deficit of replacement ewes is 4.78 million, which results in only 40 million Merino ewes available in 2004/2005.
At this level the national flock is unsustainable resulting in a shortage of mutton supply and replacement ewes.
Improving weaning percentage and keeping ewes for another lambing (five instead of four) will help sustain self replacing flocks.
A “wean more lambs” workshop which is available through Meat and Livestock Australia and NSW Department of Primary Industries provides the most current information for producers to improve weaning percentages. Contact your closest sheep livestock officer for further information.
The flock structure model is available from the Sheep CRC website at www.sheepcrc.org.au. Producers are encouraged to use the model to determine the effect of different management decisions on their own self replacing flock to assist in budgeting for the next year.
Contact: Ashley White or Brent McLeod 6349 9777