Updates to Terminal Sire Evaluation

Signet are pleased to inform clients that with the recent February evaluation we have been able to:

1. Updated breeding values for abattoir traits

New genetic relationships have been fitted within the National Terminal Sire Evaluation between those traits that are measured on-farm and at the CT unit, and those expressed at the abattoir.

This change is particularly important for breeders, who have supplied Signet with a large number of abattoir records in recent years such as the Dorset Centurion Group (to supplement the data we get from RamCompare).

Genetic relationships are now fitted between

• Scan Weight and both Days to Slaughter and Carcase Weight
• Muscle Depth and Carcase Conformation
• Fat Depth and Fat Class

Breeding values derived from the CT scanner, such as gigot muscularity, CT lean weight and CT fat weight are also taken into account.

This research confirms the current direction of travel is working. Selection for growth characteristics is having a positive impact on finishing times and our investment in ultrasound and CT scanning services has led to marked improvements in carcase quality.

More importantly, by fitting these genetic relationships into Signet’s genetic evaluations, we will produce more accurate breeding values for abattoir traits; these will be helpful for commercial ram buyers.

The Breed Benchmark has been updated to reflect these changes, which has resulted in a degree of re-scaling for the growth traits 8-week weight and scan weight and inevitably animal’s indexes will have changed; at a population level there will be a small degree of re-ranking.

You can now see abattoir derived breeding values listed on breed benchmark.

 

2. Generate genomic breeding values for the Suffolk, Hampshire Down and Charollais.

Genomic information (data that directly reflects the genetic variation in an animal’s DNA) has a wide variety of potential uses, including the verification of parentage and the ability to report major genes, such as scrapie resistance.

When it comes to breeding programmes, the use of genomic data can greatly enhance the accuracy of our breeding values, particularly for traits that are expressed in one sex (like milk), expressed later in life (like ewe longevity), are hard/expensive to measure (like methane or meat eating quality) or have a low heritability (like lamb survival). In sheep-breeding programmes it also increases the robustness of comparisons between flocks and, potentially, between breeds.

By using genomic breeding values, ram breeders and buyers can make better breeding decisions, identifying elite breeding lines among the better animals and giving new, unknown breeding lines a fairer starting point in our evaluations. In some cases, sheep that have genomic information will get informative breeding values even if they have not themselves been measured. This does not mean breeders don’t need to measure sheep but that they may be able to be more selective in their measurements.

Additionally, by doing a good job at measuring sheep in one closely related population, they may be able to make robust predictions of genetic merit in another. This is useful when the trait concerned is hard or expensive to measure.

Our genomic services have started with the Suffolk, Hampshire Down and Charollais as the three breeds that have the most genotypes available (over 10,000 in total). This work will pave the way for genomics in other breeds as genomic datasets become available.

Updated breeding values are now available at www.signetdata.com – please drop Signet Signet@ahdb.org.uk a line if you would like a new electronic report emailing out.

 

Top tip for breeders

Take any opportunity you can to get important stock sires genotyped; this will increase the accuracy of the breeding values produced for them and their lambs, helping ram buyers to make better breeding decisions. It will also help ram breeders to make faster rates of genetic improvement in the future.