Published Wednesday, 6th February 2013 in SAC Consulting news
Pregnancy scanning is as important to sheep farmers these days as expectant families. Scanning results can help save costs and reduce lamb losses.
Following one of the wettest years on record, when many ewes are approaching spring lambing in poor condition, experts from Scotland’s Rural College (SRUC) are warning farmers their scanning results will be more important than ever in planning the management and feeding their flocks.
Normally farmers look to scanning results to tell them which ewes are carrying single lambs, twins or triplets. This year it will be just as important to identify ewes which are not carrying lambs. The poor grazing and diseases of 2012 have already affected conception rates, but according to SRUC Sheep Specialist Dr John Vipond, there are fears many more ewes then normal may lose their lambs after conception.
One risk factor is the Scmallenberg virus, carried by midges from the continent and already causing problems south of the border. Scotland seems to have escaped so far but the industry remains on the alert. Presently there is more concern about the effects of parasites like Liver Fluke and Toxoplasmosis, both of which flourish in wet conditions and put additional strain on sheep already in poor condition.
It is because of these factors that John Vipond believes farmers will see an increase in the number of scanned ewes showing no lambs or smaller lambs. Thin ewes ovulate fewer eggs, have a higher chance of re-absorbing the foetus or fewer resources to grow lambs. He warns that if the numbers of barren ewes scanned are above 4 – 5%, red warning lights should be flashing. It will be important to give better attention to the pregnant sheep remaining.
Farmers should use conventional scoring techniques to asses the condition of these ewes in order to plan remedial treatment and feeding. Strangely, even in these times there will be sheep that are too fat as well as too thin. They will each need different treatment in separate groups, as will those ewes carrying one lamb or multiples.
To reduce losses Dr Vipond gives a number of tips. Make it as easy for the sheep to feed as possible and don’t let old feed lie around. Thin ewes, first time lambers and shy feeders should be given extra space.
With the upset season sheep may not be eating the usual amount of feed. Farmers should also remember growing lamb(s) will press on the rumen stomach, reducing intake. He recommends checking the dry matter of the feed and encouraging the intake of poor silages by adding 0.5 kg per tonne of sugar beet pulp pellets, or putting molasses on top. High protein additives like distillers dark grains can help low protein hay or straw. However any changes to the diets should be made gradually and not upset the rumen.
Sheep that are too fat may have been taken indoors off wet pastures. To avoid lambing problems John Vipond believes they should lose weight. He recommends giving them only the amount of silage they can clear up in a few hours, or replacing silage with straw at weekends.
However John Vipond reminds farmers the importance of the last 6 weeks of pregnancy. It is when around 75% of lamb birth weight is deposited. The demand for nutrients, along with the production of colostrum and the growth of the lamb’s birth coat puts a great strain on the ewes’ protein reserves. Supplementary protein is important for all ewes but especially thin ones. It must be digestible undegradable protein (DUP) to be effective. John suggests feeding an extra 100 g of soya bean meal per lamb carried per day for the last 3 weeks of pregnancy. It also provides energy, so concentrate levels can be reduced accordingly.
Dr Vipond is available for comment on 0131 535 3215, 07989 863874 or email@example.com.
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