As the grazing season comes to an end on many lowland sheep farms across the country, thoughts are now turning to housing the ewe flock prior to lambing. Some farmers will also include shearing as part of the housing routine.
Research from Teagasc showed that sheared ewes produced lambs – regardless of litter size – that weighed 0.6kg heavier at birth and 1.9kg heavier at weaning, compared to lambs from unshorn ewes.
In addition, lambs from winter shorn ewes were two weeks younger at slaughter compared to lambs from unshorn counterparts.
Teagasc research also showed that shearing ewes at housing had no effect on ewe body condition score and did not affect lambing difficulty.
It was noted that the increased birth weight of the lambs from the winter shorn ewes was due to increased intake of silage dry matter (DM).
This is partly due to the cold stress (intake is increased) immediately post shearing, and more importantly, a reflection of reduced heat stress when ewes are housed in the run up to lambing.
Shearing at housing also increases ewe gestation length by approximately 1.5 days, which will also contribute to greater lamb birth weights.
Also lambing problems – such as a head turned back or a head only presentation – can be detected earlier when ewes are without their fleeces.
Winter shearing ewes is better suited to mid-season lambing flocks that lamb from the month of March onwards.
This is due to the requirement for ewes to be housed for a minimum of eight weeks – post shearing in December – to allow for sufficient wool regrowth.
Naturally, this can lead to health-related problems, but this can also result in the ewe mis-mothering her offspring and – thus – negatively impacting lamb performance.