This zone is characterised by winter rainfall and hot summers with no effective rainfall. Crops form a substantial part of enterprises and most properties have stubbles available for grazing. Pastures are predominantly a mix of annual grasses, sub clover and medics.Due to a shorter growing season than the medium rainfall zone the constraints of lower feed on offer and total pasture production (2-5t/ha/yr) affect the recommendations for optimum ewe management. These all affect the potential stocking rate and pasture utilisation and therefore affects some of the recommendations for ewe management.
Optimum Ewe Condition Score TProfile
Production from ewes and their progeny can be predicted with confidence if the condition of the ewe throughout the season is known. Using these known production levels and matching them with the pasture available for the time of lambing and expected supplementary feeding costs allows an optimum ewe Condition Score (CS) profile to be developed. The profile sets the CS targets for key times during the reproductive cycle. Ewe CS at joining and at lambing are the key points on the profile with condition at lambing being the most important.
Key Points about the May Lambing Profile:
Maintaining condition from joining through to lambing is the most profitable approach to managing ewes for a may lambing in the 300-420mm zone.
The shape of the profile is as important as the actual starting condition score of the ewes, so if ewes are in CS 3.5 pre-joining the most profitable approach is to maintain their condition through to lambing. Similarly if the ewes CS is 2.5 at joining the most profitable approach is to maintain their condition.
Ewe CS for joining is influenced by the condition post-weaning and therefore it is important to monitor changes in ewe condition between weaning and joining.
The higher the lambing CS of the ewes the lower ewe and lamb mortality will be, especially in twinning ewes.
Losing condition (or not regaining condition) in the period before lambing has the biggest impact on lamb survival and progreny production.
Ewes will regain condition on green feed post peak lactation (~30 days).
More details on the economic impacts of managing ewes and the cost of missing targets can be found in the Economics section.
Detailed production impacts can be found in the Ewe Management section or click on the topic below;
Pasture photos, condition scoring and feed budgeting guides for managing ewes to CS profiles can be found in the Tools section
The economic analysis that supports these recommendations is generated using the Eastern Wheatbelt MIDAS model. A full report of the modelling for this region will be posted on this site in October 2007.
For more information on lifetimewool in South Australia contact;
Dr Janelle Hocking Edwards or Katrina Copping
Ph: 08-8762-9191
SARDI, Struan Research Centre,
Naracoorte, South Australia
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