Top tups add to lamb value
CROSS-BRED lambs sired by high index tups are worth £2 a head more when marketed compared with the progeny of low index sires, said Scottish Agricultural College (SAC) geneticist Geoff Simm, at the World Sheep and Wool Congress held this week in Malvern, Worcs.
The financial gain is the direct result of the lambs maturing 11 days earlier than their lower merit contemporaries.
They also have about 1% more lean and 3.5% less fat, with 70% of the leaner carcasses falling into the desirable 2 and 3L fat class when slaughtered.
Results are based on trials using high or low index Suffolk rams mated to Scottish Mule ewes.
Their lambs were reared at grass to produce 16.5kg, 20kg or 23.5kg carcasses.
"A recent trial has found significantly higher saleable meat yield from the carcasses of selection line progeny than from control line progeny, both at a constant carcass weight and a constant level of fatness," said Dr Simm.
• Congress report next week.