The booklet can be found HERE.

AgriSearch have published a booklet summarising the results of the RamCompare NI research project – ‘The effect of sire muscle EBV on lamb performance and case quality’. The three year study was carried out by AFBI and funded by the Department of Agriculture, Environmental and Rural Affairs (DAERA), AgriSearch and Dunbia. The programme was also supported by AHDB, Sheep Ireland and LMC.

Genetic improvement in commercial sheep flocks is mainly achieved through the purchase of breeding rams. However, when it comes to purchasing rams, there is often a strong emphasis placed on the visual appearance of the animal, together with the local reputation of breeders. As such, it has been reported that only 40% of UK sheep producers use estimated breeding values (EBVs) to select rams. EBVs are calculated based on the animal’s own performance, as well as that of its relatives and progeny. The values assigned to an animal are then used to predict how its progeny will perform in relation to the breed average. EBVs are available for a range of performance traits and thus, are a valuable tool in ram selection, allowing producers to invest in the most suitable ram to achieve the desired breeding objectives of their flock. Through the use of clear and targeted breeding objectives, a flock can progress its rate of genetic gain and associated level of performance.

The objective of the RamCompare NI project, which is aligned with the wider RamCompare UK programme, was to evaluate the use of EBVs in sire selection and flock performance. As part of this research programme, AFBI undertook experimental work with the primary objective of evaluating the performance of lambs bred from rams of a high and low genetic potential (or EBV) for muscle depth.

EBVs for production traits such as muscling, growth and fat depth have become more widely available within the UK and Ireland. Muscling EBV provides an assessment of the depth of the loin muscle and therefore is an indication of lean meat yield. Furthermore, in the last number of years the implementation of genetic improvement schemes in the UK have led to significant improvements in lean growth potential. Therefore, it is important to have a better understanding of the impact of muscling EBV on overall lamb performance and carcase quality.

The results of the study showed that by selecting rams with a high muscling EBV resulted in lambs reaching target slaughter weight 10 days earlier than lambs sired by low muscling EBV rams. This alone is a direct saving for farmers, through a reduction in production costs and increased production efficiency. It is clear that estimated breeding values (EBVs) are a valuable tool for implementing targeted breeding objectives from which farmers could see a substantial return, with the potential for even greater improvements by selecting for more than one EBV.

In addition the study found that lambs sired by high muscling EBV rams were leaner at slaughter, however carcase conformation was similar to those sired by low muscling EBV rams. This could be due to a number of factors and is an area that will require further research.

Edward Adamson, AgriSearch Sheep Committee Chair said, “The results of the RamCompare NI study clearly prove that EBVs are an invaluable tool for all farmers to use to achieve their desired breeding objectives. Regrettably the uptake of breed performance recording and the use of EBV in the NI sheep sector is relatively small in comparison to the mainland UK and the Republic of Ireland (ROI). Genetics play a crucial role in improving a flock’s production efficiency, which in turn strongly influences the economic and environmental sustainability of the farm. Given the extent of the economic and environmental challenges facing the agricultural sector farmers can ill afford to ignore the benefits of using EBVs.”