Texel initiative pays breeders
SINCE the Texel Sire Reference Scheme started in 1991 improvements in performance have justified breeders investments.
Ram lamb muscle depth at 135 days has increased by an average 0.8mm. The top ram lambs, from which next years scheme sires are selected, achieved between 39mm and 42mm. Weights at this age have improved by 1.40kg over the same period. The elite reached between 69kg and 73kg.
As a result average lean index now stands at 128.3 points, compared with 100 in the base year. The highest index is 263 points.
The benefits of using high index rams was proven in a trial using the Antur flock at Aberswyth, Wales. There, progeny sired by high index, rams were 3kg heavier 14 weeks after birth than those sired by tups with low indexes.
This years schemes performance results are derived from 38 members flocks – comprising some 3500 ewes – which are obliged to record flock performance with Signets Sheepbreeder service.
The objective of the scheme, which started with 21 flocks and 2000 ewes, is to produce high performance stock for crossing in commercial flocks, says scheme secretary Peter Johnson.
"Muscle depth, total lean content and growth rate are examples of traits we are targeting – whilst maintaining fat depth," he says.
Future objectives include gene mapping, with a bent towards isolating genes directly associated with muscularity, as well as disease resistance. The Texel is renowned for its resistance to roundworms, he says, and he is keen the breed benefits commercially from this characteristic.
Reference rams are progeny tested prior to final selection for use within the scheme. So, breeders can analyse progeny and performance test results.
Another distinction is that fresh semen is more readily available as rams spend about two months travelling the country so that semen is fresh for AI. The advantage is that cervical AI has higher conception rates than laparascopic AI – the only option when frozen semen is involved.