Breed Enhancement

The WHSS Signet Recording Scheme is now well established and for those members who are interested in joining the scheme or buying recorded stock here is a report on progress so far and details on how to join the scheme. New participants may qualify for funding from the Society, see the NEWS page for further details.

Wiltshire Horn Performance Recording Update

Introduction

This report provides an overview of the achievements in performance recording Wiltshire Horn sheep to date. The Signet Breeding Services Wiltshire Horn dataset now includes detail from 14 flocks and a total of 432 ewes and 8 - 900 lambs per season.

The following Wiltshire Horn flocks are currently involved in performance recording:

 If you wish to know more about buying recorded stock or start recording your flock, give any one of us a call; contact Sam Boon at Signet Breeding Services Tel: 0247 647 8829 or see http://www.eblex.org.uk/returns/

Performance recording provides an independant method to assess the breeding merit of animals in your flock.  This is evaluated using Estimated Breeding Values (EBVs) which indicate the genetic superiority or inferiority for a specific trait. EBVs provide important information to make informed breeding decisions and act as a valuable marketing tool. Importantly, they provide a way to add value to your rams at sales, at home and on-line. It is now possible to research details of any individual Wiltshire Horn Sheep included in the Signet Recording programme on the Basco website.  http://www.egenes.co.uk/bascosearchsheep/search/quick  Recording will quickly identify genetic strengths and weaknesses within any flock relative to all other recorded animals within the breed.  It will also identify elite ewes with potential to produce a future stock sire.

When a new flock starts to record, EBVs of sheep brought in from a recorded flock are transferred to the new flock. Sheep with a recorded sire, dam or grandparents receive initial EBVs based on their relatives’ performance. Sheep with no known records receive initial EBVs based on average genetic merit of other animals with unrecorded sire and dam of similar age and sex. Once progeny have been produced these starting EBVs are likely to change rapidly.
 

The Wiltshire Horn Breeding Index has been designed to enhance the productivity and  profitability of Wiltshire Horn sheep by increasing the weight of lean tissue in the carcase, whilst minimising any associated rise in carcase fatness and enhancing the maternal ability and prolificacy of ewes retained for breeding purposes. The Breeding Index is calculated by combining EBVs, using appropriate economic weightings, into a single figure that highlights an animal’s breeding potential for a specific breeding objective. EBVs indicate the superiority or inferiority of genes an animal possesses for a specific trait compared with other animals in the same evaluation. The EBVs for an animal are influenced by measurements relating to the trait, related traits and information collected on relatives. The Wiltshire Horn Breeding Index provides EBVs for:

• Litter size (lambs born live or dead/ewe)
• 8-Week weight (kg) (selection on high 8-week weight EBVs result in faster growing lambs to weaning)
• Maternal ability (kg) (component of 8-week weight measure;  high figures indicate females performing well as mothers – maternal care and milking ability)
• Scan weight (kg) (selection on this trait will increase growth rate to scanning at 21 weeks of age)
• Muscle depth (mm) (selection for high muscle depth will increase lean meat content of carcase)
• Fat depth (mm) (selection for low or negative measures will reduce fat levels or enable lambs to be taken to higher weights without becoming overfat)
• Mature size (kg) (gives breeders chance to influence the mature size of their flock) 

Wiltshire Horn National Breeding Evaluation Report Signet Breeding Services provides a copy of the annual Breeding Evaluation Report to each recorded flock. The Report includes a listing of the top recorded stock sires and top ram lambs within the breed. The report also includes a Breed Benchmark for the breed for the year, illustrating the difference in breeding potential for each EBV between the top and bottom 1%, 5%, 10% and 25%. The Benchmark also gives the breed average for each EBV assessed. Lists of top recorded stock sires and top recorded ram lambs in index order are followed by results specific to one’s own flock. All ram and ewe lambs produced by ewes in your flock in the current season are listed in identity order together with their individual EBVs and Index. The report goes on to list and provide up to date data on shearling rams, shearling ewes, stock ewes and stock rams in your flock. Finally lamb genetic trends and ram progeny numbers for the flock, for each year recorded are tabulated for quick reference.
 

‘High Five’ Wiltshire Horn Ram Lamb Report For the second year running Signet produced a special ‘’High Five’ Wiltshire Horn Ram Lamb Report’ listing the top five ram lambs from the 2010 lamb crop in each recorded Wiltshire Horn flock in the country as a guide to both commercial and pedigree breeders that are interested in purchasing a recorded Wiltshire Horn ram. This report has provided a useful way to promote recording in other breeds and it is hoped the same will be true for Wiltshire Horns.

Breeders meet annually with Signet consultant Sam Boon to discuss the Reports and their interpretation, progress to date, plans for future recording and continued co-operation between flocks. Following discussion at the 2009 meeting the Wiltshire Horn Breeding Index was updated ahead of the 2010 recording year, placing slightly less emphasis on prolificacy in order to reduce the incidence of triplets in favour of twins. In addition increased emphasis was placed on other important traits such as carcass quality, lamb growth rate and maternal ability.
 

Achievements to 2010 There has been a major increase in performance recording within the breed over the last five years creating a firm foundation for this important breeding improvement programme.

Funding support From 2006 until 2010 recorded flocks based within the South West of England received funding towards the cost of recording with Signet Breeding Services from the South West Rural Enterprise Gateway. This support is gratefully acknowledged and was key to getting performance recording of Wiltshire Horn sheep off to such a good start. However, from 2011 onwards, funding support will no longer be available. In spite of this news, the breeders concerned voted unanimously at the annual meeting in October 2010 to continue recording as it had proved invaluable as a management tool and considered a worthwhile investment of both time and money.
 

Genetic progress across the recorded population and within each individual recorded flock is encouraging. All flocks are moving forward, improving growth and carcase traits (lamb 8-week weights and scan weights have increased, in line with improved carcase composition), without compromising litter size and maternal ability.
 

Flock Linkages When analysing data from a large number of lambs reared in different flocks, under different management conditions the genetic linkage (shared genetics) required to enable good comparisons between flocks can be limited. To improve linkage a number of flocks have exchanged rams during 2009 and 2010, either by purchasing, loaning or sharing top recorded sires. As a result, half of the recorded flocks now have linkage considered ‘acceptable’ whilst others have plans to improve links in 2011. This will provide further potential for improved 8-week and 21-week lamb weights.  For more information read Pedigree Pointers 1 & 2 is on "Flock Connectedness" and "Accuracy Values" published by Eblex see www.eblex.org.uk/betterreturns
 

Scanning In 2010 most recorded lambs were scanned for muscle and backfat depth at 21 weeks of age. These measures were taken on the live animals using ultrasound scanning technology (similar to pregnancy scanning) across the third lumber vertebra - to get a picture of muscle and fat deposition across the loin.
 

N.B. Signet has the ability to evaluate data relating to carcass attributes, specifically muscle and fat depth. Where flocks are able to ultrasound scan their flock the EBVs for muscle depth and fat depth for their lambs will reflect measurements on these animals and their relatives. Unscanned lambs are still assigned muscle depth and fat depth EBVs in the analysis, as their breeding potential for these traits can be predicted based on other measurements. The most important of these correlated traits is live weight, with faster growing, heavier animals tending to have the genetic potential to be more heavily muscled and slightly fatter.  Where relatives have been ultrasound scanned in previous years and in other flocks this will also contribute towards predictions for muscle depth and fat depth.
 

The main reason for ultrasound scanning lambs is to find fast growing, well muscled sheep that are not overfat.
 

Mature Size Increasing lamb growth rates will inevitably increase ewe mature size on commercial farms. On some farms this is not a major issue, with larger ewes commanding a premium as breeding animals or at culling time, on others it creates an unwelcome cost due to increased feed costs and lower stocking rates. However if the trait is not measured changes cannot be assessed and sheep with the required mature size genetics cannot be selected. Signet recorded flocks submit mature weights for their shearling ewes prior to first tupping to enhance the accuracy of the mature size EBV produced for Wiltshire Horn sheep.
 

Shedding Data Recorded flocks regularly submit data on shedding characteristics of shearling ewes when shedding takes place at approximately 12 months of age with the aim of evaluating this trait in individual animals and developing a shedding EBV. Signet is working with Wiltshire Horn breeders to investigate the genetics associated with shedding, identify the optimum time and way to score the trait and over time identify whether or not high scoring animals produce the highest percentage of shedding progeny in pure and cross breeding programmes. A group of Wiltshire Horn recorded flocks won a Genesis Faraday Spark award to investigate the genetic influences on wool shedding. These data on shedding will represent an important contribution to progress with this study.
 

Flock Book advertisement In 2010 Signet and the Eblex Better Returns Programme provided funding for a full page advertisement in the Breed Society Flock Book listing all Wiltshire Horn recorded flocks. They will again support the publication of an advertisement in the 2011 Flock Book for which grateful thanks from all participating flocks are due.
 

Breed Society Sales Considerable interest from commercial breeders in purchase and future availability of recorded stock was noted at both the annual Breed Society Show and Sale at Stoneleigh and at the first Wiltshire Horn Sheep sale at Exeter market. (See the News section for sales reports). For some this interest was followed up resulting in sales of rams off farm later in the season. The feedback from these sales is awaited with interest.
 

Future plans

• Continue flock recording including scanning at 21 weeks of age
• Continue to improve linkages across all recorded flocks by exchanging or sharing rams
• Improve genetics of top ram lambs by putting the top 20% of ewes to higher EBV sires
• Provide a wider spread of shedding data by scoring earlier when only 20% of shearling ewes have fully shed
• Encourage more breeders to start recording their flocks
• Explore opportunities to increase the number of flocks collecting faecal egg count data with the aim of producing a worm resistance EBV some time in the future
• Hold an open day to promote recorded Wiltshire Horn sheep 

Open Day At the 2010 breeders’ meeting it was decided to hold an open day on 9th June 2011 to promote recorded Wiltshire Horn sheep and flock recording, with a focus on the genetics and benefits of wool shedding. The event will be supported by Eblex Better Returns Programme and will include presentations by research scientists, Eblex consultants and sheep breeders/farmers as well as a farm tour. Owners of recorded Wiltshire Horn flocks and representatives from the Wiltshire Horn Sheep Society will be in attendance. Full details about this event will be published in the farming press.