Why performance record?
The Roussin breed is primarily a maternal breed. You cannot look at a ram and know how well his daughters will milk or whether his daughters will have more lambs than another ram, so how do we do it? We record data on birth weight, lambing ease, weight at 8 weeks, scan weight and muscle/fat depth (ultrasound). By knowing the pedigrees, we can start to predict which rams’ progeny are more likely to be more successful by knowing the performance of related sheep and understanding how this translates to the next generation.
Data is submitted to an analysis tool (BLUP analysis) through Signet Breeding Services. They are able to eliminate any effect on performance, from different feeding regimes or farm environments, using data from related sheep in different flocks (termed genetic linkage).
The breed is rooted in performance recording in France. In the UK, we take breed development seriously and understand the need for farmers to use these figures as a competitive advantage. Performance recorded members can be found here with a ‘PR’ next to their surname.
Data behind the figures
Over the last five years, the Roussin breed has seen an increase in numbers of flocks recording and collecting valuable performance datasets.
The dramatic increase in numbers since 2017 is partly due to more flocks coming on board and collecting data after the Roussin Index was modified in 2017.
The Roussin Index
In 2017 Signet introduced a new Roussin Index.
The new index focuses on terminal traits increasing the weight of lean tissue in the carcase, whilst minimising any associated rise in carcase fatness, but will also:
- Enhance maternal ability
- Reward sheep with ‘optimum prolificacy’
- Place some downward pressure on ewe mature size
- Penalise the leanest breeding lines
This brings the Roussin breeding index more in line with the breeds current breeding objectives.
Although it is still early days for the performance recorded Roussin, we are already seeing genetic improvement in both growth and carcase traits. The graphs below show breed improvement in eight week weight, scan weight and muscle depth over the last five years while keeping levels of finish relatively static.
While the graphs above show genetic progress, the on-farm changes are most relevant to commercial breeders. Below is an example of the progeny differences between two rams in the same recording flock in 2018.
On the same farm, in the same year, under the same management system and lambing period the progeny of ram two produced lambs with a faster growth rate and greater loin muscularity.
These on farm improvements are ‘easy-gains’ for simply identifying and using a better ram with improved performance characteristics. While the above example compares a bottom 10% and average ram, the same can be done for high and low figured animals where we would expect to see even greater difference in on farm performance. Many ‘high-low’ trials are published in literature and are extensively used to demonstrate the on-farm benefits of using high performance genetics to both commercial and pedigree sheep breeders.
For more information on performance recording your flock please contact Signet Breeding Services.