Pedigree breeders and sheep industry stakeholders recently got the first viewing of Ovigen, a new research project aimed at fast-forwarding advancements in sheep breeding. The €1.1m project, funded by the Department of Agriculture, Food and the Marine, is being led by Teagasc and Sheep Ireland, with collaboration from UCD.

Explaining the background to the project, Teagasc’s Noirin McHugh said a limitation of getting greater buy-in and adoption of new genetics among pedigree and commercial breeders is low accuracy levels of genetic evaluations.

In simple terms, the low accuracy that an animal will deliver on its predicted breeding values and variability in genetic evaluations is reducing farmer confidence and limiting adoption of new genetics at farm level.

Increasing accuracy levels, and in doing so improving genetic gain of sheep flocks, is the core focus of the project.

According to Noirin, this will be achieved through four avenues: increased on-farm recording, improved parentage data, superior genetic evaluations and genomic selection.

While the four areas are separate criteria, collection of data is interlinked. Looking at the first three criteria, the sheep sector is at a lower starting point to beef and dairy herds due to the lower volume of breeding and performance data recorded.

For example, recording of sire details and production data through the Suckler Cow Welfare Scheme and subsequent programmes has improved accuracy of sires directly and also through strengthening genetic links.

This is clearly seen with the average accuracy of a newborn calf in Ireland recorded at 55%, while the accuracy of a newborn lamb is just 18%.

Collection of data is harder to achieve in a sheep setting with parentage data only really recorded by pedigree farmers and multiple sire mating taking precedence in many flocks over single sire mating.

However, if successful, the programme has the potential to deliver gains faster due to the shorter generation interval.

Data recording

There has been an improvement in data recording in recent years with membership of the LambPlus pedigree recording scheme rising from under 100 members in 2009 to over 600 members today (increased from about 200 in 2009 to over 600 in 2014).

On the commercial side, the Maternal Lamb Producer Scheme (MALP) flocks single sire mated 3,500 in 2014 with the four central progeny test (CPT) flocks AI-ing 2,500 ewes in October 2014.

According to Sheep Ireland’s Eamon Wall, both of these initiatives are critical in collecting on-farm data from commercial flocks and it is hoped that this data will be added to from other commercial farmers through schemes such as the Sheep Technology Adoption Programme (STAP) or through the Teagasc BETTER farm sheep programme.

Plans are also being put in place to expand the range of traits recorded and volume of data with lambing criteria, such as lamb vigour and mothering ability. It is also envisaged to target data such as lamb quality, ewe mature size and milk yield.

While these criteria are subjective and are open to variation between producers, it is hoped that the volume of data collected will contribute to an overall accurate estimation or production trend.

New web screens have been developed by Sheep Ireland to aid better recording, with work ongoing to expand the range of information collected and make systems more user-friendly.

Sheep Ireland also committed at the meeting to getting data analysis and evaluations back to breeders quicker than in previous years, which should help to strengthen relationships.

Noirin said the integration of all flock books into the Sheep Ireland database will also aid in improving evaluations and is a core element of getting more accurate information back out to breeders.

Developing links with international breed society databases, particularly in France and the UK, where a significant number of ewes and rams are imported from, is also an essential component to getting more background information and increasing accuracy of these animals faster.

Talks between Sheep Ireland and Eblex in the UK (concerning Texel and Charollais) are reported as being at an advanced stage, while negotiations are ongoing with French breed societies.

The launch of the new Inzac trial in Teagasc Athenry earlier this year also opens up greater links with New Zealand and the potential to compare elite Irish and New Zealand genetics.

Across-breed evaluations

Another piece of the breeding jigsaw is the development and introduction of across-breed evaluations. This will allow animals to be ranked within breed and across breed, ie how they compare to the average of all breeds in the database for particular traits. Noirin said getting breeder co-operation is the most important aspect, with the success of the trial influenced greatly by the volume of data collected.

Genomic evaluations

The final research aspect of the Ovigen trial is genomic evaluations. Noirin said that genomic selection is useless without first having sufficient data available on the breed. The starting point is therefore to genotype all ewes and rams from breeds with sufficient data in the Sheep Ireland database.

She said that at the outset, the focus will be on breeds rather than just individual breeders.

The plan presented at the trial briefing is to genotype approximately 12,000 animals across five breeds with sufficient data available in 2015. The breakdown of testing is shown in Table 1.

In addition to this, testing will also begin on other breeds outside of these five to identify if relationships exist that will allow them to be incorporated easily into genomic evaluations.

Cheap parentage options are also being investigated to allow breeders with animals not selected for the testing to carry out their own testing and quickly build the volume of data on the Sheep Ireland database.

Keeping all breeders and breed societies informed of decisions made and results achieved will be critical to build and maintain strong co-operation.

Starting date

The trial starts in March 2015 with DNA collection in the five main breeds. This will be carried out by Sheep Ireland technicians and Eamon Wall said collection of DNA samples will also be used as an opportunity to collect data on criteria such as ewe weight, body condition score, lamb weights, etc.

It is envisaged that visits will start taking place once lambs are old enough and hardy enough to be handled.

DNA collected will be owned and stored by Sheep Ireland, but can be used for other evaluations if required.

Where breeders want to collect samples outside of the animals selected by the Ovigen project, Sheep Ireland will collect and store the data, but breeders will have to cover the costs themselves (currently costing about €30 per animal for full range of DNA analysis).

Presentations from the day and further information can be found on the Sheep Ireland website at www.sheep.ie.

Main LambPlus recording breeds

The breeds with the greatest number of lambs recorded on the Sheep Ireland database in 2014 are detailed in Figure 1. According to Eamon Wall, the volume of data recorded by the Texel, Charollais and Suffolk breeders in recent years has led to significant improvement in the accuracy of evaluations.

However, as shown in Figure 2, there is still a large percentage of ewes in the makeup of the national flock with low numbers of lambs recorded.

In particular, there is huge potential for hill flocks and increased data recording in the Scottish Blackface and Cheviot breeds.

What genomics can deliver

While genomics has been introduced in recent years, firstly in dairying and then beef, it is new to the sheep sector. Explaining genomics and what it can deliver, Teagasc’s Donagh Berry said genomics has the potential to fast-forward breeding and greatly enhance the accuracy of genetic evaluations.

Taking the example of the average ram, he said accuracy before breeding is only 18%. This is due to the fact that, on average, 50% of genes are passed on from the father and 50% from the mother, so it is difficult to predict what traits the ram will pass on to his progeny.

When an animal completes its progeny test, with 100 of his lambs for example, there is more of his DNA expressed in the population. This contributes to the accuracy of what traits are likely to be expressed in progeny.

In its simplest terms, genomics identifies what DNA is linked to the expression of particular traits. By identifying this, it is possible to look directly at an animal’s DNA after it is born and make predictions on the traits it is likely to express with greater accuracy rather than waiting for it to be expressed in progeny.

Donagh said that because genomics in sheep is relatively new, it is hard to quantify what the increase in accuracy will be. Experience from the dairy sector shows genomics having the potential to increase accuracy levels to 76% or the equivalent of performance data from 54 milking daughters.

He said that genomics will never deliver 100% due to certain phenotypes (traits) that are typically affected by more than one gene or the interaction of a number of genes or the fact that certain genes interact with the environment in different ways.

Despite this, he said it can offer huge potential to the sheep sector.

It will not be an overnight solution but rather a long-term initiative that will hopefully influence pedigree breeding and in turn get more productive genetics flowing into commercial flocks.