Lamb mortality under three lambing systems

Abstract

Three systems of lambing management were compared at Trangie in Central Western New South Wales. A supervised system involving daily drifting of ewes through a series of small paddocks was first compared with an unsupervised system in which ewes were set-stocked in a single large paddock (A) and later, an unsupervised system in which ewes were set-stocked in sub-flocks according to their expected date of lambing (B). Lamb loss associated with the management of marking and mulesing proved to be an important factor in the comparison. The introduction of unsupervised system (B) was associated with a reduction in losses after marking compared with the supervised system. Lamb loss prior to marking was lowest in the supervised system. Of the three systems, unsupervised system (B) is considered the most suitable for areas in which environmental conditions during lambing are not harsh.