Australian Livestock Scanning Services Group

The results and recommendations from 23 years of on-property R&D with commercial sheep and cattle producers. We specialise in precision scanning for pregnancy, twinning, and ageing of foetus in sheep and cattle and in helping to raise lamb survival and cow fertility in stud and commercial breeding enterprises.

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8. Optimise feeding costs - a feeding strategy for pregnant ewes

Supplementary feeding is costly and must therefore be practiced as effectively as possible. Improved pasture is often in short supply and given a high cost of establishment, must also be used as efficiently as possible.

Pregnancy scanning enables the following decisions to be made:

  1. When to start a feeding program; where the twinning percentage is low and the fat score of the single-bearing ewes is adequate, proposed feeding programs can delayed or postponed.
  2. Which ewes to feed; often it is the twin-bearing ewes only that have been started on a supplement or given access to limited amount of improved pasture, or higher quality natural pasture available. The rest of the ewes in the flock have often started much later, or have not been supplemented at all.
  3. Projected feed requirements; where the numbers of dry, single and twin-bearing ewes, fat score and pasture availability are known, the producer has most of the information required to determine the amount of feed needed.
  4. What feed quality is needed; the twin-bearing ewes have often needed a protein based supplement whilst the single-bearing ewes have been able to get by with a cheaper energy based supplement. Producers who regularly scan their ewes have learned the extent to which the nutritional demands of single-bearing ewes are lower than that of twin-bearing ewes.
Single bearing ewes that are due to lamb in the last weeks of lambing should be identified and put into the lambing paddock 16 to 20 days after the main start of lambing.

The cost of scanning and feeding

The cost of scanning and feeding is usually less than that of feeding the entire breeding flock, but even when it is similar, the producer obtains more for the same dollar input.

For many producers, scanning is a regular part of the management program, even in years when pasture is abundant. In those years, ewes identified as single-bearing have been able to have their nutritional intake restricted. This strategy can lift lambing percentages in single-bearing ewes, by reducing the incidence of difficult births among the later-lambing ewes.

Producers, who scan their ewes every year, do so in order to match the nutritional needs of the breeding ewes with the demands at the varying stages of the reproductive cycle.

In the following table, the theoretical amount of feed required to maintain a dry ewe in each month of the year is taken as 1. As a guideline, the additional feed required for the maintenance of ewes of a differing pregnancy and rearing status is shown; as a multiple of that required to maintain a dry ewe.

Ewe status
Dry ewes
1.0 1.0
Single bearing 1.7JPJP JP
Twin bearing ALALALAL

AL: Ad Libitum feeding (Feed as much as possible to get the ewes heavy and fat for joining).
JP: Joining Preparation (Feed to get the ewes heavy and fat for joining). Each column after the first represents 1 month of the year.

The correct nutritional management of the pregnant ewe plays a major role in the quality of wool produced by the next crop of lambs.