Do 5-star sheep really perform better at farm level?

With a population of 2.74 million breeding sheep, there’s substantial scope to increase the genetic merit of the Irish flock.

At a recent Sheep Ireland industry meeting, Teagasc researchers outlined how making genetic merit improvements – specifically the use of €uroStar indices – can have a major impact on profitability at farm level.

Presenting data from Central Progeny Testing (CPT) flocks, along with the INZAC flock, Teagasc’s Dr. Fiona McGovern highlighted the performance differences between 1-star (low genetic merit) and 5-star (high genetic merit) animals.

More lambs and less mortality

Starting with an analysis of the CPT flocks, which compared 5-star and 1-star animals on the Replacement Index, Fiona explained: “With 5-star animals, we were seeing lower lamb mortality levels, which is beneficial because you have more live lambs on-farm.

“We were seeing high numbers of lambs born. This is again great because higher numbers of lambs born, combined with low mortality, means we are going to have more lambs to sell at the end of the year.”

Looking at performance in terms of the Terminal Index, she said: “We’re seeing the 5-star animals are having a lower lambing difficulty percentage, so less of the ewes needed to be handled at lambing.

If we look at the 40-day weight, the 5-star lambs were – on average – 2kg heavier than the 1-star lambs. This carried forward to weaning, where we were seeing that the 5-star animals were over 2.5kg heavier than the 1-star animals.

INZAC flock

Fiona also presented data from the INZAC flock in terms of the differences witnessed between 5-star and 1-star ewes on the Replacement Index.

“The 5-star animals are having lower lamb mortality percentages and higher numbers of lambs born. They’re reflecting what’s happening on CPT flocks.”

Continuing, she said: “Using 5-star animals means you are going to have less lambing difficulty and, maybe, there won’t be as intensive of a need for handling ewes at lambing.”

Touching on the performance of lambs born to the INZAC flock, she said: “Where we are getting heavier lambs at weaning from 5-star ewes, they’re 15 days shorter to slaughter than our 1-star animals.

They are reaching their desired slaughter weights quicker, which means that they are off the farm quicker.

“Animals that stay on the farm longer – and take a longer time to reach their slaughter weight – require extra feeding and that’s an extra cost to the system,” she said.

Economic performance

Through the use of an economic model, Fiona showed the differences witnessed between 1-star and 5-star animals in terms of monetary value.

“We’ve seen that the net profit per hectare from the 1-star treatment group was €7; but our net profit per hectare from the 5-star treatment group was €217.”