A gulf in genetic potential could open between pedigree and commercial sheep flocks on both sides of the Irish border as a strategic sheep breeding programme in the Republic of Ireland expects to deliver nationwide genomic testing results by the end of 2019.

Speaking at an NI Texel society meeting on Monday, Teagasc researcher Noirin McHugh outlined the progress being made on sheep research projects south of the border.

Over 5,000 Irish flocks are now recording data through the Lamb+ programme, aimed at increasing data records and parentage links across pedigree sheep, thereby improving the accuracy of breeding indices.

The data is then used to give breeding rams and ewes a €uro-star rating for commercial flocks, with five stars indicating higher terminal or maternal ability that will deliver more profitable lambs.

Genomics

Genomic testing is improving the accuracy of data recording and linkage between sheep.

McHugh confirmed that genomic testing has shown that 10% of pedigree animals are registered to the wrong sire, with 15% registered to the wrong dam.

Genomics eliminates these errors, and can increase data accuracy of recorded traits to more than 60% for lambs as young as two days old, she said.

According to McHugh, it is then possible to identify lambs with potential for breeding in the first week of life.

Selecting traits

Almost 19,000 sheep have now been genotyped in Ireland and the science can identify specific genes for desired traits.

For instance, the BMP15xb gene is linked to ewe prolificacy. If ewes possess one copy of this gene, ovulation rates are higher.

Average lamb numbers are increased by approximately 0.53lambs/ewe.

A single copy of the gene is present in just 0.07% of the national flock, yet almost 10% of Belclare sheep carry the gene.

However, if a ewe has two copies of the gene, then the animal is sterile and unable to breed, and identifying this early means these lambs are sold fat much earlier.

International links

With a high number of imported breeding sheep from the UK and France, Teagasc has linked up with research facilities in both regions to harness breeding data within their breed societies, again improving the accuracy of Irish breeding data.

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