RamCompare: phase II

RamCompare, the UKs national progeny test, launched in 2015, is a joint-levy funded project, led by AHDB with continued financial support agreed in 2017 to collect data for an additional three years.

Phase II recruited additional farms and widened the reach of genetics to include performance-recorded rams from all terminal-sire breeds. Data was collected from birth to slaughter from lambs reared in a commercial environment from ten farms located across the UK.

This data built our understanding for the new abattoir-derived breeding traits, developed through phase I, allowing additional estimated breeding values (EBVs) for Primal Yield, Meat Tenderness and Days to Slaughter to be released in the first year alongside an Overall Carcase Merit Index provided for each ram on test. The increasing dataset allowed a clearer understanding of the relationship and heritability’s between live-animal proxy traits of the Terminal-sire rams used and the abattoir-derived traits from their cross-bred commercial lamb progeny.

The project has shown how commercial farmers can improve efficiency and reduce the cost of lamb production through the selection of superior rams, while providing breeders with important information to enhance their breeding policies and increase rates of genetic gain.

Results are made available on the RamCompare/Signet website. Through interpretation of the results we draw out ram highlights as case studies with breed-specific stories or through individual farm features.

More information can be found at RamCompare | Signet Breeding (signetdata.com)

• Project overview

• Farm profiles

• Rams on Test

• Results

• Case studies

The Problem

This proposal addresses three key problems impacting the economic sustainability of the sheep industry:

• A high proportion of prime lambs slaughtered are not meeting the required market specification
• A low proportion (40%) of terminal sire sheep for breeding are selected on the basis of estimated breeding values (EBVs) which improve the efficiency of production
• Sheep are not being improved in some important areas of productivity because EBVs do not address all the traits of economic importance to sheep producers

According to the sheep carcase classification report, around a quarter of lamb carcases are not in specification (defined as classification class of O or P, and/or fat class of 4L, 4H or 5) (AHDB, 2016). Genetics is part of the solution to this industry problem, as carcase traits (growth rates, muscle and fat levels) are highly heritable.

Defra survey work has established that only 40% of sheep holdings use EBVs when selecting rams for breeding. New traits, such as days to slaughter, can help accelerate genetic progress and deliver sheep that more closely meet the needs of producers.

Aims and Objectives

The project will be evaluated against a set of milestones, key deliverables, time and budget.  A number of key performance indicators will be monitored and reported including:

• The number of levy payers, and target industry stakeholders, changing their purchasing behaviour or advice, measured through surveys and focus groups
• The number of opportunities for each levy payer to see and hear the key messages with the aim of changing purchasing decisions, measured through surveys of breeders and producers
• Measuring the progress in the proportion of in-spec lambs on the network of farms established by the project by analysing abattoir data and using this within the KE plan
• Return on investment and cost benefit to levy payers

In the long-term, monitoring genetic trends for the commercially-focussed EBVs and uptake of relevant EBVs by the industry using surveys offers a way of measuring sustained impact. It is challenging to use industry data (e.g. carcase classification report) to confirm activity as it is affected by the number of factors, including weather, prices and other economic factors.

Approach

The main environmental impact of sheep production is currently seen to be that of greenhouse gas (GHG) emissions. Reduced days to slaughter mean that the GHG emissions of rearing a lamb from birth to slaughter are reduced proportionately, thus reducing the impact of sheep production on climate change.

The projected saving of 18 days to slaughter represents approximately 9% increase in growth rate. In the Change in the Air – Road Map (EBLEX, 2009), it was estimated that a 15% increase in growth rate equates to a 6% reduction in global warming potential (GWP) from GHG emissions. For those farms achieving a 9% increase in growth rate to slaughter it is not unreasonable to assume a 3% reduction in GWP on those farms.