| |
HOW TO BUY THE RIGHT BLACKFACE TUP FOR YOUR FLOCK - A QUICK GUIDE TO BUYING BLACKFACE TUPS
USING ESTIMATED BREEDING VALUES (EBVs)
This page provides an explanation of:
Introduction
Blackface tups are required to produce:
- Lambs that grow well with good carcases
- Daughters that possess good maternal abilities
It is impossible to identify animals with ‘good genetics’ for these traits ‘by eye’ however, since:
- Environmental factors such as feeding greatly affect a ram’s appearance, and
- Some traits are only expressed in his daughters.
Illustration of main 'Environmental Factors' affecting animal performance.
How Can a Tup’s Breeding Potential be Assessed?
All members of bfelite measure growth, carcase and maternal attributes using Signet’s Sheepbreeder Service.
Data is analysed to take the environmental factors and genetic relationships between animals in to account. Estimated Breeding Values (EBVs) are produced from this analysis to identify animals with superior breeding potential.
- EBVs provide an accurate assessment of a tup’s breeding potential for commercially important traits
- EBVs are even more important when selecting a tup for maternal traits, such as maternal ability and litter size, which can’t be observed in males.
- By matching EBVs to a producer’s flock objective, the tup best suited for the job can be found.
What are EBVs?
EBVs predict the superiority of a ram’s breeding potential for specific traits. These are as follows:
EBV |
What Does It Indicate? |
Look for… |
8 Week Weight (kg) |
The genetic potential for growth from birth to 8 weeks of age. |
High positive EBVs if you want high lamb growth to 8 weeks of age |
Litter Size (%) |
The genetic potential to breed prolific female progeny, (which lose fewer lambs) |
High Positive EBVs if you want good prolificacy in the daughters (who also lose fewer lambs) |
Maternal Ability (kg) |
The potential to breed ewes with good maternal ability and milkiness, expressed by lambs’ performance to 8 weeks of age |
High positive EBVs if you want daughters that will rear high total lamb weights to weaning |
Mature Size (kg) |
The genetic potential for size at maturity |
High positive EBVs if you want progeny that are large at maturity. |
Scan Weight (kg) |
The genetic potential for growth from birth to 20/21 weeks of age (weaning). |
High positive EBVs if you want high lamb growth rates to weaning and heavier carcases. |
Muscle Depth (mm) |
The genetic potential for muscularity and potential to increase lean meat yield. |
High positive EBVs if you want good lamb conformation |
Fat Depth (mm) |
The genetic potential for leaner carcases. |
High negative EBVs if you want lean lamb carcases or lambs that will go to heavier weights without penalty for fatness. |
Index (points) |
Sheep with the right breeding potential to enhance the returns of a commercial hill flock, based on the different EBVs listed above. |
High Indexes identify animals that will produce more productive females and fast growing lambs. |
What is the Hill-2 Index?
A Breeding Index combines information on different EBVs in to a single figure, using appropriate economic weightings, to meet a specific breeding goal. Different Indexes have been constructed to meet the different breeding objectives of British sheep breeds. All Blackface flocks use the Hill-2 index, made up from the following EBVs:
Maternal Ability EBV
|
 |
|
Litter Size EBV
|
|
Mature Size EBV
|
Hill 2 Index |
Growth (8 week EBV & Scan weight EBV)
|
|
Muscle Depth EBV
|
|
| Fat Depth EBV |
|
Using EBVs and Indexes is Easy!
Go Back to top
To establish how an animal compares to the rest of the breed use the ‘Breed Benchmark’:
Breed Benchmark
The breed Benchmark is published annualy and gives values for all 7 traits (EBV's) against which all animals in the breed can be compaired.
Click here for the most up to date Breed Benchmark information
Tips on Using EBV
- FIRST CONSIDER WHICH TRAIT(S) YOU WISH TO CHANGE IN THE FLOCK?
- What are your breeding objectives?
- Which trait(s) will make you most money?
This will help you to decide which EBVs are most relevant to you, and the priority they should be given
- OBTAIN THE BREED BENCHMARK
- EBVs and Indexes are produced for Blackface sheep on a ‘Whole Breed’ basis. This means that EBVs and Indexes in one flock can be directly compared to those in another. The Breed Benchmark shows the current average for the breed, the Top 25%, Top 10% and Top 1% (as well as Bottom 25%, 10% and 1%). It is updated each year and will allow you to see how an animal compares to the rest of the breed for each trait and Index.
- DISCUSS YOUR REQUIREMENTS WITH THE BREEDER who will help select tups with the combination of EBVs to meet your requirements.
- IT IS IMPORTANT that you also carry out your own assessment of type and structural soundness of an animal you are considering using for breeding.
- NEVER BE IN DOUBT ABOUT EBVs. Details and further help is available from a variety of sources:
- The Breeder (at home and at sales)
- Bfelite <bfelite@btinternet.com or 01899 830 225>
- Pen Cards and Catalogues at sales
- Signet Telephone: 01908 844195
|
