Jamie is a general practice vet with a
focus on sheep and beef systems
and works in Vetlife’s Central Otago
and Twizel clinics.
The farming calendar never stops, but certain times of year are a good opportunity to measure and reset. Lamb weaning is one of these events. For a ewe, the breeding season starts again when her lambs are removed.
A Body Condition Score (BCS) of less than three means she may struggle to mate well and produce large, healthy lambs the following spring.
Two main goals of Body Condition Scoring ewes at weaning:
The target condition score for ewes at weaning is 3 out of 5 or better. This is best measured by feeling the backbone and short ribs behind the ribcage. A 3/5 ewe will not feel “prime”, but her back muscle will be slightly rounded. A little pressure will be required to feel the short ribs (the small bones pointing sideways off the backbone).
Once ewes are weaned their feed intake drops dramatically and their efficiency at putting weight back on is actually less than while lactating. Ewes are able to gain weight in the month leading up to weaning when feed and weather allow. For these reasons it is ideal if ewes can reach weaning at a good weight, rather than milking off their backs and regaining the weight afterwards. A dramatically different spring compared to last year means that this might be a realistic target in 2024/25.
Ewes with a BCS of less than 3 can be preferentially fed by running in front of the main ewe mob, on summer crops, or by sharing finishing pastures with lambs. A double benefit to grazing alongside lambs is the ‘vacuum’ effect of ewes on parasite larvae, protecting the lambs from parasite challenge as well as delaying resistance.
Calibrating your eye (and hands) to condition score accurately requires regular practice. We are happy to visit when ewes are yarded and demonstrate condition scoring to you and your staff.
Factsheet by BeefandLambNZ
