RamCompare: phase I

The RamCompare project has released final results for the first stage of the project which spanned 2015-2017 breeding seasons.

Since preliminary results were released in November 2017, the data set has been updated to include records from later-lambing flocks not included in the first run and analysis has been modified to enhance the way hybrid vigour is taken into account. This has led to some re-ranking of rams based on their carcase weight EBV.

Penygelli, PAP1501802, a Texel ram bred by Alwyn Philips, has moved into the top position for the carcase weight estimated breeding value (EBV) and overall carcase merit. Penygelli PAP1501802 is a high-index ram sired by Boghouse Ultramuscle, one of Alwyn’s stock rams. Boghouse Ultramuscle was sold to RamCompare and is being progeny tested this year on the project farm run by the Edwards family in Wales.

The Charollais breed has a new leading sire, with Logiedurno Navigator 13ZNN07239, nominated by the Crogham and Coldharbour Charollais flocks, sitting high in the overall rankings for carcase weight EBV and carcase value.

Amongst the Suffolk rams tested, Whichford First Class, bred by Bruce Cook, has now joined the list of the highest ranked Suffolk rams for carcase weight EBV.

Bridget Lloyd, RamCompare Project Coordinator, said: “With all rams from the first two breeding seasons now included, the final results tables show a slight repositioning. This will continue to happen each year as more rams are included in the trial with data regularly coming in from the farms and abattoirs.

Drinkstone Distinction (Y68:A20) will be used on all eight RamCompare farms, with his lambs creating a link between each farm to enable comparisons to be made. Distinction was born in 2002 and was an elite sire in his day with over 460 progeny. He is still an important sire with an index in the top 5 per cent of the Suffolk breed. His semen is available to breeders who want to use him as a benchmark within their own flocks.

More information on the rams with semen on offer can be found at RamCompare | Signet Breeding (signetdata.com)

The Problem:

Combined breed analysis (CBA) was debated at Sheep Breeders Round Table in November 2013 and it was agreed that it was a target for the UK sheep industry. This would mean that terminal sires would be analysed using the same baselines so estimated breeding values (EBV) for different breeds could be compared directly.  AHDB Beef & Lamb have been in discussion with EGENES to see if existing data from some ram breeding flocks using different breeds and cross-breeds can be used to establish CBA.

It is proposed that a central progeny test (CPT) would be useful to helping to validate the CBA work, as commercial progeny data from different breeds of rams being used on the same farm would be extremely useful.

The review of genetic improvement of beef and sheep in the UK suggest that one of the recommendations will be the establishment of a CPT. As it has been shown in other countries that CPT help to improve genetic gains.

Aims and Objectives:

• To collect and collate data from over 6,000 lambs, sired by high genetic merit rams from the main terminal breeds, from several commercial farms and abattoirs
• To collate and include data from a variety of sources – written records, electronic identification (EID) systems, software programs, abattoirs – in current breeding evaluations
• To use commercial data to improve the development of the CBA
• To investigate the relationship between on-farm measurements of performance (growth rate, ultrasound scanning of muscle and fat depth) and industry measures of economic value (carcase weight, days to slaughter, carcase conformation and fat class)
• To explore if the genetic ranking of rams reared on intensive diets is similar when progeny are reared under forage-based commercial conditions
• To examine how the performance of progeny of different terminal sire breeds compares under commercial conditions
• To test the feasibility of running a CPT

Approach:

A partnership of levy boards (AHDB Beef & Lamb, HCC, QMS and AgriSearch), EGENES, Evidence-based Veterinary Consultancy, Randall Parker, Dunbia, Elanco, Allflex, Shearwell, Premium Sheep and Goat Health Scheme and Sainsbury’s will be developed.

Six commercial flocks will be selected based on robust criteria and recruited for two breeding seasons (tupping 2015 and 2016).

Rams with top 20% EBVs for growth and carcase traits will be identified from Texel, Suffolk, Charollais, Meatlinc and Hampshire Down breeds by Signet Breeding Services.

120 ewes per farm will be artificial inseminated to AI sires that will be rotated across farms and years to create linkage.  200 ewes will be mated in single sire groups to five rams.

EID will be used to identify the ewes and lambs would need to be tagged and recorded at birth.  Performance records would include live and dead lambs, birth weight, lambing ease, eight week weight, 90 day weight and sale weight.

Slaughter date, carcase weight and classification would be collected and assigned to EID tags.  Additional carcase information in the form of VIA scanning, saleable meat yield and tenderness measurements would be collected on a proportion of carcases.

After year 1, a quick comparison of ram performance will be produced and discussed within a technical working group, but these results will not be released to the industry.

After year 2, a full genetic analysis will be undertaken and results will be presented in the form of tables showing the top 25 rams for Eight week weight EBV, Scan weight EBV, Muscle depth EBV and Fat depth EBV.  This will mean, for the first time, rams of different breeds can be compared directly. The project would provide data to allow future development on new EBVs for days to slaughter and carcase weight.