Sheep Ireland breeding advice for selecting rams has always centred on judging an animal on a combination of physical traits and predicted breeding performance.

At last week’s genetics conference, head of sheep enterprise at Salesian Agricultural College David Coen told those attending that were it not for access to genetic evaluations, a ram that is now excelling in the flock could have met a premature end.

David said that in 2015 the flock purchased a Belclare ram, Kilflynn Amigo MN1511041, which at the time had a good replacement index value of €1.22, but could have been characterised as not possessing superior physical attributes.

He explained: “The ram was a triplet that weighed in the region of 45kg. He had sound physical attributes in terms of legs, feet, teeth, conformation, etc, but was light and looked to some to be closer to a factory ram than a breeding ram.

“We decided to take a chance on his genetics and have been hugely rewarded since,” he said.

The purchase of the ram coincided with the flock putting much more attention into data recording.

David explains that there has been a sheep flock in the college for over 60 years, but that there was very little data recording taking place until recent years.

The flock joined Sheep Ireland in 2016 with the aim of establishing current performance and identifying the best- and worst-performing ewes.

Ewes were assessed on breed, age, weight, body condition score, etc, with this information used to develop a primary profile.

Across-flock comparison

In 2016, ewes were artificially inseminated to Central Progeny Test (CPT) sires. This gave the opportunity to evaluate the flock against linked flocks, while the collection of higher volumes of data helped to increase the accuracy of genetic evaluations.

Kilflynn Amigo was then widely used in the flock in 2017. Figure 1 shows the average replacement index of females in the flock, with a complete turnaround achieved in the last six to seven years.

David explains that ewe lambs have followed a continuous upward trajectory, with ewe lamb replacements possessing a higher value than the average of mature ewes, demonstrating that the flock is moving in the right direction.

The average replacement index of females in the flock was €0.195, with an accuracy of 40% in 2018.

The average replacement index of females lambing down in 2019 is €0.915, with 42% accuracy.

The jump in the replacement index value has been underpinned by Kilflynn Amigo’s genetic evaluation soaring in 2017, with the replacement index value now standing at €4.86, while the terminal index has increased to €2.01, with the accuracy of predictions now at 78% and 81% respectively.

The increase has been such that the ram has been used in four pedigree flocks in 2018 and through the CPT flocks.

This is a situation David is particularly pleased about: “For our flock to continue to record progress, we need access to superior genetics, which are becoming harder to source.

“It is important that pedigree breeders utilise the best genetics to make this happen and we are glad to be in a position to be able to help.”

Five-star genetics delivering

The flock is now starting to deliver on some key performance indicators. A higher daughter milk yield potential is delivering in higher output, with ewes rated as four and five stars for daughter milk achieving a litter weight at 40 days of 7kg higher than one-star ewes and 2kg higher than three- and four-star rated ewes.

The lamb survivability rating of ewes has also improved, with over 106 ewes rated five-star for lamb survivability, while there are 43 four-star ewes, 36 three-star ewes, 29 two-star ewes and 33 one-star ewes.

David believes this is contributing to lower lamb mortality, which has improved from 13.03% in 2016 to 11.75% in 2017 and 9.49% in 2018.

David concludes that management still remains vital to flock performance, but that without recording performance you will not be able to make decisions that will influence management practices with any degree of accuracy, while there is also the risk of losing the flock’s best genetics.