Keep a Close Eye on Ewe Body Condition Score

13 September 2019

Managing ewe Body Condition Score (BCS) must remain a high priority this year following exceptional grass growth despite uncertainty facing the industry

Rosie Miller from Trouw Nutrition GB argues that despite the uncertainty in the sheep sector it is essential to manage ewes correctly in pre-tupping, tupping and early pregnancy.

“The next three months go a long way to setting a maximum for sheep farmer returns as they will determine the size of the potential lamb crop. With considerable speculation about lamb prices, markets and tariffs next year there is little that can be done about price, so the objective must be to make sure you have as many lambs as possible to exploit any opportunities that might develop.”

Ms Miller says managing ewe BCS is vital for ewe health and production. Management of BCS should be done throughout the year to avoid over or under conditioned ewes at lambing. She says the exceptional grass growing year in many parts of the country has had an impact on the condition of ewes as we enter the crucial tupping period.

“This season from early February to mid-August, data from the Trouw Nutrition Grasswatch service show that on average in the GB we have had over 2000 kg DM/ha more grass growth than for the same period last year.

“The increased grass availability this season, coupled with a smaller ewe flock, means that ewes have maintained condition better and so are approaching tupping in generally better BCS.”

She says data from this year’s grass silages analysed by the company so far indicate that good quality forages have been made. She says this will be a positive for lambing time when ewes need high levels of energy and protein in the diet and should allow a reduction in purchased feed use. However, BCS must be carefully managed from now through to lambing

“Target 90% of ewes in the target BCS at tupping. This is a BCS of 2.5 for hill ewes, 3.0 for upland, and 3.5 for lowland ewes. Ewes with a high BCS of over 4 at tupping may see no conception rate benefit from flushing and if flushed may increase BCS further, causing more problems at lambing unless the over condition is corrected.

“It is quite likely we will see ewes carrying too much condition at this time of year due to the grassy summer.  Ewes above average BCS should be kept on a level plane of nutrition through early pregnancy and then slowly try to reduce excess BCS during mid pregnancy.

“Daily energy intake for maintenance will be 8-10MJ depending on the size of ewe and this should be achievable from grazing this year as growth remains high and quality good.”

During early pregnancy, she says embryos are vulnerable to stress, so steps to reduce stress during this period should be taken. Key to this is managing BCS pre-tupping to avoid having to adjust BCS during early pregnancy. Also try to avoid major diet changes.

“While it may be tempting to cut corners with management to save costs in the face of insecure future markets, taking steps to maximise the lamb crop should still be a priority,” Ms Miller concludes.