Teagasc research and advisory staff held a store lamb finishing open day last week in Mellows Campus, Athenry, Co Galway. The event was aimed at providing farmers with the latest advice on finishing store lambs on autumn pasture and all-concentrate intensive finishing diets.
The role of grass in the diet of finishing lambs is diminishing in line with a reduction in grass quality. Farmers attending the event were told that the typical daily liveweight gain of lambs during November could be in the region of 80g/day to 110g/day, dropping to 50g during December and January.
This is provided lambs have access to good-quality grass and reasonably dry underfoot conditions to give rise to favourable grass utilisation.
If utilisation is poor and grass dry matter is low, lambs will do well to maintain weight, with low-level concentrate supplementation (300g to 500g) required to hit these weights.
Light lambs
While the performance figures described above are low, they may fit into a system where light lambs are being carried over the winter and develop a frame before being intensively finished.
This is an approach taken by many specialised finishers in recent years to take advantage of rising farmgate returns in March and April.
It has also been an unavoidable production system adopted by others in the absence of traditional light lamb markets, with producers having no option but to try to bring light hill lambs close to French lamb weights and at least in excess of 14kg to 15kg carcase weight.
Finishing blueprints
Numerous studies have been carried out in the last four years in Athenry to identify suitable finishing blueprints for purebred and crossbred hill lambs with varying starting weights.
These blueprints were outlined by sheep enterprise leader Michael Diskin, sheep specialist Frank Campion and PhD student with the trial Noel Claffey.
The advice given, irrespective of the type of lamb, was to exhaust the potential of grazed grass where possible. This is not giving licence to retain lambs outdoors at the expense of grass supplies for competing ewes, but rather is aimed at optimum management and best use of autumn and winter grass supplies.
As mentioned above, this will bring lambs to a heavier liveweight at the start of the intensive finishing period, which will help hit target carcase weights and reduce the length of the finishing period.
Lamb finishing study 1: light lambs
Lamb finishing study 2: starting at heavier weights