26 October 2001

Top rams and group mating achieve high margins

GROUP mating and high index rams helped produce margins of £44 a ewe in an early lambing flock at Greenmount College.

The Northern Ireland-based college achieved these results with January-born Suffolk-sired lambs, finished on grass supplemented with ad-lib creep feed. They reached an average of 20.5kg deadweight.

The trial is part of the colleges five-year Suffolk breed evaluation known as LAMBS, Learning Advances in Management and Breeding with Suffolks. The project also aims to demonstrate new sheep breeding technology, ewe performance and examine lamb production costs.

High index Signet recorded Suffolk rams are being used in two flocks totalling 120 ewes. The flocks comprise Suffolk x Cheviot and Rouge x Texel ewes, explains Greenmount Colleges sheep technologist Steve Johnston.

Group mating was used in both flocks with one ram turned out with a maximum of eight ewes 48 hours after sponge removal. The rams were left with the ewes for 48 hours.

"This practice appears labour intensive and does require good management, but we believe it is justified by the increased lambing percentage. This year we achieved 1.68 lambs reared a ewe. We believe the group mating contributed to an overall reduction in cost/kg of lambs reared by increasing the amount of lambs produced a ewe and by reducing mating costs," says Dr Johnston.

Ewes and their Suffolk-sired lambs were turned out 10 days after lambing and creep was introduced when lambs were three weeks old. Creep consumption was 42kg a head and ewes were fed 75kg a head.

Lambs exceeded the target finishing weight by 2kg, he adds. They were sold off their dams within 16 weeks and averaged 20.5kg.

Variable costs were £1.05/kg dead-weight of lamb. Direct costs, which include variable and replacement costs, were £1.34/kg deadweight, below last years costs of £1.81/kg. &#42

Flock mating results/lamb performance


Target Suffolk x Cheviot Rouge x Texel

Ewes lambing (two cycles) 85 89 88

Lambs born a ewe in-lamb 170% 200% 187%

Lambs reared a ewe in-lamb 155% 184% 151%

Growth rate

To 11 weeks (g a day) 300 400 314

To slaughter (g a day) 350 364 335

Carcass wt (kg) 18 20.6 20.4