Pregnancy scanning and using the results
Head of Sheep Knowledge Transfer in Teagasc, Michael Gottstein details the benefits of pregnancy scanning ewes and highlights how to make use of the results to achieve significant cost savings at farm level.
Pregnancy scanning to identify which ewes are pregnant and to predict the expected litter size is now a common practice amongst most lowland sheep flocks. It is also being practiced by a significant number of hill flocks.
Many sheep flocks will be in the process of getting their breeding flocks pregnancy scanned, if this has not already happened.
Pregnancy scanning is a relatively cheap and highly cost effective practice, provided that the information is subsequently used to target supplementation according to litter size, body condition and lambing date.
The ideal time to scan ewes is between day 45 and 80 of pregnancy. From a practical point of view, it is generally recommended that scanning takes place 80 days post ram turnout. To aid the scanning operator to successfully identify the litter size, it is a good idea to have the ewes fasted for eight to 10 hours prior to scanning. This is to reduce the area taken up by stomach contents.
Using the results
Post scanning and depending on the facilities that are available, ewes should be divided into at least three groups. At a minimum, these divisions should consist of:
- Single-bearing ewes in good body condition and empty ewes (where these are being retained and not sold post scanning);
- Twin-bearing ewes in good body condition and single-bearing ewes in poor body condition;
- Triplet-bearing ewes and twin-bearing ewes in poor body condition.
On farms where sheep are being housed and penning allows for further divisions then ewes should also be divided according to lambing date. The savings in terms of concentrate feed being offered to later-lambing ewes can be significant and this practice also reduces the incidence of oversized lambs in later lambing ewes.
To reap the full benefits of scanning, it is essential that ewes are fed according to litter size and body condition. On many farms, ewes are managed as a single group and this benefit is lost. In addition to identifying litter size, scanning time also represents and opportunity on most farms to handle the flock and assess body condition. Use this information and separate ewes that are in poor body condition for preferential feeding. This will pay dividends when they lamb next spring.
Michael featured on a recent episode of the OviCast Podcast. For more useful tips on managing your ewes post scanning, listen in below: