Breeding Better Mums

“Breeding Better Mums”

A Genesis Faraday Industry Club Award

Summary

This project was developed to enable pedigree beef breeders to recognise the commercial value of enhancing maternal traits through selective breeding.
Activities were delivered to encourage the pedigree breeder to breed from cattle with superior maternal attributes and to assist commercial bull buyers to preferentially select these bulls for breeding purposes. 
Activities ranged from on-farm meetings to the production of informative technical material that was mailed directly to producers.

Over its duration the project produced: 
• Press articles (including Sheep and Beef Notes articles) 
• Two mailings to nearly 500 performance recorded herds
• The production and distribution of a Sire Summary to nearly 1000 Society members in the Red Poll, Ruby Red Devon, Lincoln Red and Sussex breeds
• A Sire Summary and Promising Young Bull listing for the Stabiliser Breeding Group
• Three case studies to show the importance of genetic selection in maternal breeds of cattle
• A range of breed specific meetings
• A PowerPoint presentation for consultants relating to maternal traits
• A series of meetings with commercial producers in association with EBLEX 
• A new set of sale cards to display and promote EBVs

Information has been well received and will lead to lasting change in the way Estimated Breeding Values are used by pedigree breeders. 
 
Background

New maternal traits and maternal breeding indexes have been developed for the first time in the UK for beef cattle breeds.   This technology has not been available before and a core group of innovative breeders from each of the industrial partners are keen to develop their knowledge and apply the principles within their herds.

Objective: 
(i) To provide breed specific guidance to individual breeders and breed societies on the opportunity to enhance maternal performance through selective breeding using a series of new EBVs.
(ii) Encourage pedigree breeders to develop appropriate breeding goals within their performance recorded herds.

The key barriers to the uptake of the new technology are: 
1. The breeder’s uncertainty of the practical requirements needed for performance recording.  
2. Maternal traits and indexes were not available for use until now and in particular native cattle breed societies could not see the value of performance recording without this information.  
3. Performance records have only recently become accepted and valued by commercial buyers seeking maternal sires.

Activities

A range of activities has been completed to educate both commercial and pedigree producers with a view to overcoming some of the barriers to adoption listed above.  Signet has worked with these Breed Societies on a one to one basis and enlisted support from SAC/EGENES, EBLEX and HCC to assist in the wider dissemination of information. 
Signet has communicated with breeders and commercial bull buyers directly at meetings, farm open days and through the distribution of written materials. A series of new materials have been produced including two new beef manuals (with support from EBLEX and HCC), data input forms and Sire Summary publications for the numerically smaller breeds.  
Over the last 18 months the industry faced two health breakdowns due to Foot and Mouth disease and Blue Tongue. To an extend these biosecurity risks limited the number of on-farm events held during 2007 and the willingness of other parties to get involved in organising collective breeder meetings. As a result it was decided that more time would be spent in the production of materials for distribution via mail – such as the new Sire Summary which was produced as an additional extra to support the project.
The principle activities are listed below, together with supporting materials in the accompanying appendices.

1). Maternal information for recording breeders
2). Publicity in the Farming Press
3). Meetings with breeders & commercial producers
4). Sire and Dam Summaries for Maternal Breeds
5). Publications for commercial producers

1). Maternal information for recording breeders
Information sheets explaining the new Maternal traits were sent to all Signet clients at the start of the project. Members were told about the new EBVs that were about to be produced and traits that would be important in the future. 
The explanatory note outlined the EBVs that would be available on reports and the way that two new Beef Indexes – the Maternal Value and Maternal Production Value – are constructed. 
A copy of the briefing document is attached in Appendix 1.

2). Publicity in the Farming Press
A number of features on Maternal Traits have been produced and circulated to the wider beef industry.

These include:
• Sheep and Beef Notes article on Maternal Traits (AG) – Appendix 2
• Sheep and Beef Notes article focussing on Limousin Maternal Traits (BL) – Appendix 3
• Sheep and Beef Notes article focussing on Maternal Cards (BL) – Appendix 4
• Farmer’s Weekly article on Maternal Traits – Two Sussex Case Studies (SB) – Appendix 5
• NSA Beef Farmer article Signet article (reproduced by KMH) – Appendix 6.
• Farmer’s Guardian article – Buying the right bull, Christmas competition (SB with EBLEX)
• Farmer’s Weekly article – Breeding more productive cows (in press, Stabiliser case study)

 
3). Meetings with breeders

A number of meetings have been held with both pedigree and commercial producers to discuss the introduction and interpretation of maternal traits.

Pedigree breeder meetings arranged as part of this specific project have included:
• Red Poll Cattle Breeders meeting at Winterhill - 7th January
• Limousin Society meeting – Several, most recently 11th March.
• Sussex Cattle Breeders meeting in Kent – 25th April (PowerPoint in Appendix 8)
• Lincoln Red Breeders meeting in Lincoln – 7th May 
• Devon Cattle Breeders meeting in Devon  – 21st May
• Blonde Cattle Society representatives meeting – June and February

Signet staff have provided maternal breeding advice to both pedigree and commercial beef at the following industry events. 
• Beef EXPO Event – May
• Royal Show – July 
• Signet representatives have also featured information about maternal traits on display stands at major bull sales, which include Carlisle, Perth and Newark

Maternal traits have been a feature of the following commercial beef presentations. It is recognised that consultancy provided to attend these meetings has been paid by EBLEX and hence the time allocated to these five events is not being claimed from this industry club award. 
• EBLEX event in Cambridgeshire – 5th June
• Meat South West Event in Devon – 18th June 
• EBLEX event in Shropshire – 26th June
• Gloucestershire Grassland Discussion Group – 8th November
• EBLEX event in Norfolk  - 15th November

4). Sire and Dam Summary Documents for Maternal Breeds

Many non-recording pedigree producers are not familiar with EBVs, particularly in the numerically smaller breeds that are involved in this project such as the Sussex, Devon, Red Poll and Lincoln Red breeds. To educate pedigree producers a Sire Summary was produced, listing the EBVs for important recorded bulls within the breed. This enables breeders to see performance figures for animals they recognize and encourages the use of the better breeding lines in future breeding decisions. 
This is the first time such a publication has been produced for these four breeds. Copies were sent to all Society members; which involved a mailshot to nearly 1000 pedigree producers (417 Devon, 168 Sussex, 156 Lincoln Red and approximately 250 Red Polls).  
Time was spent designing the document to provide clear instructions on both the meaning and use of this important information. An extract from one of these Sire Summaries is shown in Appendix 7.
At the same time, Signet took the opportunity to mail breeders with an additional note on bull health and fertility. New breeders will have commenced performance recording as a result of this mailing.

5). Publications for commercial producers

Signet has worked with EBLEX and HCC to produce two exciting new manuals. 
These manuals explain to commercial producers the importance of breeding and feature large sections on maternal traits.

6). Publications for Breed Societies

Breed specific articles have been written for the Red Poll, Sussex (2) and Limousin Societies informing breeders about maternal traits and providing practical examples of how these new EBVs can be used to enhance herd performance.  

7). Bull Sale Cards

To assist producers to use maternal traits to make effective selection decisions a series of new Sale Cards have been produced featuring EBVs for both existing and new Maternal Traits. 
Signet are aware that as the range of traits increases it can become daunting for producers to assess an animal’s overall breeding merit. The new EBV charts provide an instant visual clue to assess the relative strengths and weaknesses of a particular bull. 
The example in diagram 3 shows two Limousin bulls with a similar Beef Value. Lot 196 excels in all traits and would leave more productive female replacements. Lot 326 has good terminal sire traits, but would be less suitable as a maternal sire. (Please do not reproduce examples without Signet permission).
These cards are now being produced for shows and sales where maternal breeds are on display, such as the forthcoming Ruby Red Devon Sale on 20th March 2008.

8). New Trait Data Collection

As part of this project Signet has commenced the recording of several new traits, including scrotal circumference, udder score, teat score and mature size. 
These traits are all genetic factors influencing the financial performance of the suckler herd, whether this is due to their influence on the longevity or efficiency of the cow. 
All Signet clients have been sent forms explaining why and how these new traits should be recorded. Data collection has also been discussed at the meetings listed above. Data is now being submitted for these new traits on a regular basis.

9). Industry Feedback

A series of internal meetings have been held with Signet’s academic partners to discuss various issues of industry feedback arising from the publication of these maternal EBVs. 
An example of which is shown below:
EBV for calving interval
Two concerns have arisen with regard to the calculation of the calving interval EBV.  The first is that a significant number of producers start mating their maiden heifers one month before the cows to give them one month longer to recover before they are mated for a second time.  
The second is the managerial restraints placed upon cows when they are mated within a seasonal calving herd.  For example the first born heifer, in a herd calving down at two years of age will be exposed to the bull when she is about 14.5 months old.  In comparison the last born heifer, in a herd with a three month calving period will be exposed to the bull at 11.5 months of age.
Over successive meetings/teleconferences held with SAC/EGENES these issues have been aired and additional research has been undertaken to either alleviate breeder concerns or change the data collection protocol to take additional environmental influences into account.

10) Forthcoming promotional activity

Case studies form an important part of the promotional message. Giving a real life example of the financial and physical impact of EBVs in action enables commercial producers to relate to the benefits associated with the adoption of this breeding technology and encourages its use within their farming systems.
A series of stories are now in the pipeline; an example of which is shown below. This data from a well-known Stabiliser herd shows the strong relationship between a bull’s EBVs for early growth rate and the performance of his progeny. In this example the difference between the progeny of the top and bottom performing bulls at 200 days of age was nearly 40kg, a massive difference in breeding terms.

Summary

The project has been flexible in its approach to the promotion of maternal traits and made contact with pedigree breeders and commercial beef producers in a number of different ways. 
Activities that have been delivered as a result of this project include:

• Press articles (including Sheep and Beef Notes articles) 
• Two mailings to nearly 500 performance recorded herds
• The production and distribution of a Sire Summary to nearly 1000 Society members in the Red Poll, Ruby Red Devon, Lincoln Red and Sussex breeds
• A Sire Summary and Promising Young Bull listing for the Stabiliser Breeding Group
• Three case studies to show the importance of genetic selection in maternal breeds of cattle.
• A range of breed specific meetings
• A PowerPoint presentation for consultants relating to maternal traits
• A new set of sale cards to display and promote EBVs

In addition to this Signet has promoted the importance of maternal traits at a series of commercial meetings supported by EBLEX and HCC, communicating directly with nearly 800 commercial beef producers.
Information has been well received and will lead to lasting change in the way Estimated Breeding Values are used by both pedigree and commercial beef breeders to “Breed Better Mums”.

 

Appendix 1. Maternal Traits Article

NEW MATERNAL EBVS AND INDEXES IN 2006

New EBVs and Indexes are now available that will enable beef producers to identify bulls that will sire more profitable female replacements.

A.  NEW EBVs
Research carried out by SAC and funded by MLC, DEFRA and SEERAD (via the LINK Sustainable Livestock Production Programme) and supported by the British Limousin Cattle Society has identified cow size, age at first calving, reproductive success and replacement rate as the major maternal traits contributing to the profitability of beef enterprises in the UK (Roughsedge et al., 2003 ref Journal of Animal Science 2005, 81: 221-232).

A range of new maternal EBVs has been developed so that breeders can select animals with high genetic merit for these attributes.  EBVs are now available for the following traits:

1. Calving Interval (days) -ve values for cows that will get back in calf more quickly
2. Age at First Calving (%) -ve values for heifers that will reach puberty quicker
3. Longevity (years)
      also referred to as Lifespan  +ve values for cows that will have a longer breeding life
4. Maternal Calving Ease (%) +ve values for more unassisted calvings

Taking each of these in turn:

1.  Calving Interval

Definition: An EBV predicting reproductive success.  For male animals it predicts the reproductive success of female offspring.
Calculated from: Calving records and animal age are used to examine the time taken between the first and second calvings.  If no second calving appears in the data the record is set as missing.
Unit of measurement:  Days
Interpretation:  A bull with a Calving Interval EBV of -10 days will produce females that, on average, have calving intervals that are 5 days shorter than the standard 365 days.

2.  Age at First Calving

Definition: An EBV predicting the ability of heifers to calve for the first time at a young age.  For male animals it predicts the ability of female offspring to calve for the first time at a young age.
Calculated from: Calving dates and animal age.  This trait accounts for management effects i.e. is calving at three years old a policy, or is it because the animal was unable to conceive to calve at 2 or 2.5 years old?  The approach is first to determine if the farm has more than one calving season and also if different ages at first calving occur.  If no opportunity was determined to have existed to calve at an early age, then the value is recorded as missing.  
Unit of measurement:  % Proportion
Interpretation:  A bull with an Age at First Calving EBV of -0.10 will produce 5% more females that are likely to have their first calf at an early age (given the opportunity) than a bull with an EBV of 0.

3.  Longevity

Definition: An EBV predicting age at culling.  For male animals it predicts the number of calvings prior to culling in female offspring.
Calculated from:  Calving records, culling records, animal age and breed survival probabilities.
Unit of measurement: Disposal age (in years)
Interpretation:  A bull with a Longevity EBV of +1.0 years is likely to produce female replacements that will, on average, live 0.5 years longer in the herd than females sired by a bull with an EBV of 0.

4.  Maternal Calving Ease

Definition: An EBV predicting the ease with which a cow will calve.  For male animals it predicts the ease with which his female offspring will calve. .
Calculated from: Calving ease scores on the five-point scale already used for the Calving Ease (Direct) EBV and birth weight.
Unit of measurement:  %
Interpretation:  A bull with a Maternal Calving Ease EBV of 2% will produce females that have 1% more unassisted calvings than a bull with an EBV of 0.  
(Similarly, a bull with a Maternal Calving Ease EBV of –2% will produce females that have 1% more assisted calvings than a bull with an EBV of 0).
Note:  This EBV should not be confused with the Calving Ease (Direct) EBV relating to the ease by which a sire’s calves will be born.

NEW INDEXES

Two new Indexes based on these EBVs are also now available, as follows:
1)  Maternal Value
Definition:  An index predicting the overall economic value of an animal’s genetic ability to produce breeding females.  In the female it predicts the overall value of an animal’s maternal characteristics.
Calculated from: The contributing EBVs to this index are:
• Calving Interval (days)
• Age at First Calving (%)
• Longevity (years)
• Maternal Calving Ease (%)
• 200-Day Milk Weight (kg)

Unit of measurement:  £
Interpretation:  A bull with a Maternal Value of LM12V will be worth £12 more per cow mated than a bull with a value of LM0V, half of which will be realised in his progeny by merit of their maternal characteristics. 
 

2)  Maternal Production Value

Definition:  The economic value of an animal in terms of its overall genetic potential to produce female replacements for breeding and males for finishing
Calculated from:  This Index is calculated from Maternal Value, Beef Value and Calving Value, while also taking into account Maintenance Value (the costs associated with feeding mature cows within the herd).
Maternal Value
Maintenance Value
Calving Value
Beef Value

Unit of measurement:  £

Interpretation:  A bull with a Maternal Production Value of LM10P will be worth £10 more per cow mated than a bull with a value of LM0P, half of which will be realised in his progeny by merit of their maternal and carcase characteristics.  
Appendix 2. Sheep and Beef Notes Article
MATERNAL EBVs AND INDEX

Buyers of beef cattle breeds recording with MLC’s Signet Breeding Services will be able to take advantage of a new suite of Maternal EBVs.
Extensive research completed in 2003 (Roughsedge et al.) identified the following as the major maternal traits contributing to UK beef profitability:
 cow size
 age at first calving
 reproductive success, and 
 replacement rate

In response, so that breeders can effectively select animals with high genetic merit for traits that contribute to these, the first new EBVs coming available in 2006 are as follows:
• Longevity (years)
• Age at First Calving (days)
• Calving Interval (days)
• Maternal Calving Ease (%)

The table below shows what each EBV will indicate and how to interpret it when buying replacement females or bulls:

Trait Interpretation Notes
Longevity (years) +ve values = longer breeding life Predicts the length of a cow’s breeding life.  For bulls it predicts the breeding life of his female offspring. 
Age at First Calving (days) -ve values = puberty reached at an early age Predicting the ability to first calve at a young age, given the opportunity.  For bulls, it predicts their female offspring’s’ ability to first calve at a young age, given the opportunity.
Calving Interval (days) -ve values = cows that will get back in calf more quickly Predicts reproductive success.  For bulls, it predicts the reproductive success of female offspring.
Maternal Calving Ease (%) +ve values = more unassisted calvings Predicts the ease with which a cow will calve.  For bulls it predicts how easy calving his female offspring will be.  Not to be confused with Calving Ease Direct (the ease with which a bull’s progeny will be born).

Together with the existing Maternal EBV of 200-Day Milk Weight, these EBVs have also been incorporated in to a new Index, as follows:

Longevity (years)
Age at First Calving (days)
Calving Interval (days)
Maternal Calving Ease (%)
200-Day Milk Weight (kg)

As with the Beef Value and the Calving Value, the Maternal Value is calculated from the relative economic weightings of the contributing EBVs.  Its purpose is to rank animals in terms of the overall value of their maternal characteristics, complimenting the other two indexes which focus on growth/carcase attributes and terminal sire calving attributes respectively.

Four further EBVs will come available on a breed-by-breed basis as data becomes available:
• Scrotal Circumference (cm): an indicator of fertility in related females
• Cow Weight EBV (kg): an indicator of mature size of cows
• Udder Score (points): an indicator of udder size and shape
• Teat Score (points): an indicator of teat size

These in turn will lead to two further Indexes as follows:

Cow Weight EBV (kg)

Maternal Value
Maintenance Value
Beef Value
Calving Value

These EBVs and Indexes have been created using data from purebred and cross bred data collected in the UK and are unique to our beef industry.  Simulated herd exercises (SAC 2004) show that the difference between selecting a bull to breed replacement heifers on the basis of Production Value can be worth up to £42/cow mated more than if the bull were selected on Beef Value alone.  As more and more producers are retaining their own suckler herd replacements each year, these tailor-made EBVs and Indexes will help find the best animals for the job.
Alison Glasgow
MLC’s Signet Breeding Services

Appendix 3. Article in Sheep and Beef Notes

2007 EBV Values For Limousin

Each year Signet produces the average, top and bottom, 25, 10 and 1% values for the breeds which record with them.  As an example the following table shows the 2007 values for the Limousin breed.
Table 1 2007 Limousin EBVs

TRAIT BOTTOM AVERAGE TOP
 1% 10% 25%  25% 10% 1%
Gestation Length (days) 3.2 2 1 0.2 -0.7 -1.4 -3.1
Calving Ease -6.4 -4.1 -2.4 -1.5 -0.2 0.5 1.7
Birth Weight (kg) 3.1 2.1 1.6 1.1 0.5 0.2 -0.6
Calving Value LM-3C LM-2C LM0C LM1C LM2C LM3C LM6C
200-Day Growth (kg) -6 2 7 14 21 27 41
400-Day Growth (kg) -10 2 13 25 36 47 69
Muscling Score (points) -0.8 -0.1 0.2 0.4 0.6 0.9 1.3
Muscle Depth (mm) -2.6 -0.2 0.8 1.7 2.7 3.6 5.4
Fat Depth (mm) 0.4 0.2 0.1 0.0 -0.2 -0.3 -0.5
Beef Value LM2 LM7 LM12 LM17 LM22 LM27 LM37
Age at First Calving (%) 0.2 0.1 0.1 0.0 0.0 -0.1 -0.2
Maternal Calving Ease -1.2 -0.3 0.1 0.5 0.9 1.4 2.3
200-Day Milk (kg) -8 -4 -2 -1 1 3 5
Calving Interval (days) 12.4 6.5 3.7 1.2 -1.3 -3.9 -8.7
Longevity (years) -0.4 -0.1 0.1 0.2 0.4 0.5 0.8
Maternal Value LM-22V LM-10V LM-4V LM2V LM9V LM14V LM25V
Maternal Production Value LM-27P LM-15P LM-5P LM2P LM10P LM17P LM30P

The average value shows how the breed has changed since 1980 when average values of the EBVs for animals born in that year were all set at zero.  In general it is clear to see that breeders have made Limousin cattle bigger, more muscular but have lost a little of the breeds easy calving characteristics.  
Another important point which is clearly shown by these figures is the large variation there is within each breed.  As an example table 2 shows the difference in EBV values between animals in the bottom 10% compared with the top 10% of breed.  Using Gestation Length as an example there is a massive 3.4 day difference.

 
Variation in EBV Values For 2007 Limousin

Trait Difference between bottom and top 10% Animals Expected Difference In Progeny*
Gestation Length (days) 3.4 1.7
Calving Ease 4.6 2.3
Birth Weight (kg) 1.9 1
Calving Value 5 2.5
200-Day Growth (kg) 29 15
400-Day Growth (kg) 49 25
Muscling Score (points) 1.0 0.5
Muscle Depth (mm) 3.8 1.9
Fat Depth (mm) -0.5 -0.3
Beef Value 34 17
Age at First Calving (%) 0.2 0.1
Maternal Calving Ease 1.7 0.9
200-Day Milk (kg) -7 -3.5
Calving Interval (days) 10.4 5.2
Longevity (years) 0.6 0.3
Maternal Value 24 12
Maternal Production Value 32 16
* Assuming bulls are mated to cows with zero EBV values for all traits. 

As an example of this variation we can take a situation where a producer purchases 2 Limousin bulls, one having average EBV values from the bottom 10% and the other from the top 10%.
Calves sired by the top 10% bull will be born nearly 2 days earlier and with less calving difficulties even though they would have around 1 kg heavier birth weights.  This advantage increases to around an extra 15 kg by the time the calves are weaned at around 200 days of age and around an extra 25 kg by the time they are slaughtered.  They would have more muscular carcasses grading higher in terms of carcass conformation whilst being slightly leaner.  Overall this would improve carcass sale price by around £17 per head.
If heifers from the better bull were kept as replacements more would successfully get in calf as heifers and would have less difficulty calving.  They would milk well, increasing the weight of their calf due to their better mothering ability by around an extra 3.5 kg but more of them would still be able to get back in calf quickly to calve earlier the following year.  Finally heifers from the top 10% bull would have a longer, productive herd life of around an extra 4 months.  Adding all these advantages together, heifers sired by the top 10% bull would leave, on average, an extra £12 for each calf they produced.  Assuming an average output of 8 calves this would amount to a total advantage of around £100 extra profit over the lifetime of the heifer. Adding on to this the improved carcass value of the by-product steer would increase the improved profit to £16 per calf.
The problem with this exercise is that it is based on average figures whereas in practice individual animals vary widely in their EBV values.  For example an individual bull might be below average for 400 Day Weight but be in the top 1% for Ease of Calving while being just average for Maternal Production Index.  However what EBVs do provide buyers is an independent measure of each animals genetic potential – it is up to the buyer, knowing the exact requirements of his own herd, to use EBVs to select the most profitable animal for his specific system.  
Basil Lowman, SAC Beef Specialist

Appendix 4. Article in Sheep and Beef Notes

 Interpreting The New Signet EBV Cards
Signet has just produced new display cards showing the EBVs of breeding stock, particularly bulls, at sales for those breeds who record with them.  The main change is that the EBVs are now presented as a bar chart with the central line indicating the average EBV values for animals born in the previous year.  The chart is based on a standardised index score with 100 representing the average value of all EBVs.  An index above 100 is shown on the right hand side of the central line and represents the preferred EBV value which is above average.  For the majority of EBVs such as 400 Day Weight this would be a positive above average value but for some such as Gestation Length and Birth Weight a negative EBV ie below average figure is the preferred value.
Values to the left hand side of average indicate potentially undesirable EBV values such as a negative Calving Ease EBV.  These have an index below 100.
In general the display boards fall into 3 broad categories –
• Bulls with mainly average EBV values so that the horizontal bars are very short and can hardly be seen.
• A second group would be well bred bulls with the majority of their EBV bars clearly showing to the right hand side of the central protocol line.  These are bulls with large, preferable EBV values likely to be in the top 25% or better of the breed  a small and very desirable subset of those bulls on sale show positive figures for both growth and calving traits.
• The final group are those with obvious EBV bars to the left hand side of the central vertical line.  These charts indicate animals with undesirable EBV values and begs the question why were they taken to the sale in the first place.
Signet boards still display all the EBVs for all animals whether they be good or bad.  As a further aid to buyers similar groups of EBVs are coloured the same eg 
Calving EBVs – yellow
Growth EBVs – bright green
Carcase EBVs – bright blue
Beef Value - purple
Calving Value – yellow
Maternal Value – olive green

Basil Lowman, SAC Beef Specialist

Appendix 5. Farmer’s Weekly Article on Maternal Traits
Sussex returns boosted with EBVs
By Sam Boon
EBLEX Beef Better Returns Programme (Beef BRP)

A study supported by the EBLEX Beef Better Returns Programme has shown that using Estimated Breeding Values (EBVs) when choosing a stock bull can substantially increase returns both for finishers and for breeders producing female replacements.
The first part of the study examined the performance of calves sired by two recorded Sussex bulls and identified a £30/calf premium gained through better growth rates and carcase weights.
During 2005/06 the two bulls sired 67 calves in the Holm Place Sussex herd belonging to Mr John Lewis of Holm Place Farm, Sheerness, Kent. The performance of the calves was tracked and recorded and the data has been analysed by Signet to assess how they relate back to each bull’s EBVs.
Table 1 Estimated Breeding Values for Two Sussex Stock Bulls

  Calving Value - EBV  200 Day Weight  - EBV  400 Day Weight EBV  Muscle Depth - EBV  Backfat Depth – EBV  Beef Value - EBV
Bull A  5 16 41 1.5 -0.1 31
Bull B 1 26 71 2.7 0.7 43
Breed Average 2 15 35 2.3 0.1 28
*Both bulls have accuracy values for growth traits over 90 and for carcase traits over 85.
From their EBVs (Table 1), both are good Sussex bulls. Bull A has excellent genetics for ease of calving and a Beef Value just outside the Top 25% for the breed. Bull B has a 400 Day Weight EBV and Beef Value in the Top 10%. Interestingly the bull with the heaviest 400 day adjusted weight was not the one with the highest EBV for 400 Day Weight. This shows how important it is to use EBVs rather than raw data when selecting a bull. The heaviest bull at a sale is not always the one with the best genetics for growth.

The 200 and 400 Day Weight EBVs for the two bulls would suggest a 5kg (half of 26kg minus 16kg) and 15kg (half of 71kg minus 41kg) difference in the average weights of their progeny at 200 and 400 days of age respectively. In reality the difference in calf growth rates was far greater than predicted by the EBVs (Table 2).

Table 2 Progeny Performance – Growth rate

 No. of 200 Day Adjusted Weights (calves) Average 200 Day Adjusted Weight No. of  400 Day Adjusted Weights (calves) Average 400 Day Adjusted Weight
Bull A  33 237kg 34 388kg
Bull B 34 251kg 32 418kg
Difference  13kg  30kg

This high level of performance is pleasing to see and indicates the potential to lift productivity that can be achieved through the use of superior recorded sires.
In this example a 30kg advantage at 400 days of age could easily generate an extra £30-40/head for a producer finishing beef cattle – a return that could be worth several thousand pounds over the lifetime of the bull.
These findings are consistent with several recent studies in the Limousin breed where the growth rates of calves sired by high EBV bulls have exceeded predictions. This is good news for both the pedigree and commercial producer – indicating that the progeny of bulls with high EBVs are excelling under good commercial management.
Mr Lewis said: “Judging by sight alone, I prefer the poorer of the two bulls for producing calves with good conformation figures. I think this proves that EBVs are more accurate at predicting how the bull’s progeny will perform. The other bull is better at producing good heifers for breeding.
“I try and breed better sons as well, because the bulls won’t be around for ever.”
Maternal traits feature strongly within the overall breeding strategy of the Holm Place herd, which has been performance recording for over 20 years. While growth and carcase traits have improved, the breeding potential for calving ease has also risen.
In this study, no significant differences were noted in the ease with which calves sired by either bull were born – nearly all were born without assistance. This might have been because the bulls were used on mature cows and in an easier calving breed like the Sussex, subtle differences in calving ease can be hard to detect. On farms where heifers are mated at a young age, Bull A would still have been the bull of choice because of his superior calving traits.
“My experience over the years is that by taking notice of your EBVs you can gradually improve your conformation, growth rates, maternal traits and everything else,” continued Mr Lewis. “It’s difficult to quantify an increase in returns from better genetics, due to inflation and having good years and bad years, but there is no doubt that using EBVs is worth it.
“Of my heifers last year I kept ten, sold eight privately off the farm to a regular customer in Hampshire, sold two for slaughter, and the rest averaged £1,042 a head at auction.”
Overall, the project suggests that it is possible to select Sussex bulls with superior breeding potential for growth and carcase traits without detriment to important maternal traits such as calving ease and milk production. EBVs provide a good indicator of significant differences in the breeding potential of Sussex sires which has a real commercial value.

Case study: Selecting maternal sires for the beef herd – getting the balance right
An increasing number of beef producers are breeding their own female replacements. This is mainly due to difficulties in sourcing first cross dairy bred heifers with the right genetics to produce hard wearing suckler cows, and health concerns around bought-in animals.
In the beef enterprise of M K D Hind, Mayfield, East Sussex, maternal breeding decisions come to the fore in both their pedigree Sussex herd and in the breeding of commercial suckler replacements.
Farm Manager Brenda Hide believes the selection of high performing breeding stock is extremely important: “EBVs have a vital role to play when it comes to maternal traits, which cannot be assessed visually in bulls. Once we have considered the structural soundness of a potential stock bull, we spend time looking at the bull’s EBVs, starting with growth and carcase traits.
“We’re finishing cattle at 12-14 months of age, so it is important that any sire coming to Mayfield can produce well fleshed progeny that will finish off grass with acceptable fat cover. We look for sires with good 200 and 400 Day Growth EBVs, and a high Muscle Depth EBV. We also avoid bulls with extremely high or low EBVs for fat depth.”
This combination means the bulls’ progeny will comfortably make the 280-330kg target carcase weight Mrs Hide requires for the local butchers that the farm supplies.
Sires used to breed female replacements also need to have good 200 Day Milk EBVs. Brenda comments that within any breed there are breeding lines that are poorer milkers and this can be particularly noticeable when maiden heifers are calving at a young age.
While the Sussex is renowned for its ease of calving, attention is still required when selecting a bull to minimise the risk of calving problems. Mrs Hide advises caution if using a bull with a very high Birth Weight EBV, as this can lead to problems – particularly on smaller framed cows. Where possible a bull with a positive Calving Ease EBV should also be sought. Where females are being retained check the bull’s Maternal Calving Ease EBV to see how easily his daughter’s progeny will be born.
The Mayfield herd is part of a Sussex breeding group looking to increase the frequency of polled cattle within the breed. The Scottish Agricultural College (SAC) estimates the benefit in using a naturally polled bull compared to one with horns could be worth an extra £1.20/calf, due to the labour involved in dehorning. There will be other significant advantages in avoiding any potential check in the calves’ development. While the frequency of polled genetics within the Sussex breed is relatively low, the process is made easier through the infusion of Red Angus genetics and subsequent backcrossing with Sussex breeding lines to retain the polling gene.
For more information on choosing bulls to breed for better returns, contact Beef Better Returns Programme on 0870 241 8829 or email [email protected]

ENDS

Appendix 6. NBA Beef Farmer Article

Better Bulls Breed Better

Appendix 7. Example of New Sire Summary for Minor Breeds

LINCOLN RED LEADING SIRES
BLUP Analysis: 23rd October 2007

Animal Name Identity

Date of Birth Gestation
Length
(days) Calving
Ease Birth
Weight
(kg) CALVING
VALUE 200 Day
Milk
(kg) 200 Day
Growth
(kg) 400 Day
Growth
(kg) Muscling
Score
(pts) Muscle
Depth
(mm) Fat
Depth
(mm) BEEF
VALUE
  Estimated Breeding Values (EBVs)
Accuracies(%)
 ACTHORPE NELSON
   WALMER KEYSTONE
    ACTHORPE NANCY 46TH NJJ59N
15/10/1969 0.9
88 -4.1
92 2.4
96 0
93 0
93 19
98 34
98 0.3
94 2.2
97 0.6
86 21
98
 ANWICK CHANCELLOR 
   ANWICK EXODUS
   ANWICK HANNAH Z57 LK004200494
BCLC7
01/02/2000 1
82 0.4
90 0.2
94 1
90 2
67 -9
96 -10
95 0.4
91 -0.4
94 -1
87 6
96
 BEVERLEY ADVENTURER A58
   BEVERLEY XPRESS
   BEVERLEY MISS V11 L716500303
CAJA58
21/12/1998 -0.3
22 -1.8
91 0.1
88 2
85 7
53 12
95 39
95 0.7
86 -0.9
92 -0.1
71 20
95
 BEVERLEY DALLAS
   ANWICK UNDAUNTED
   BEVERLEY MISS V38 UK 141158/300050
17/01/2001 0.2
29 -1
58 0.8
55 1
51 2
45 19
73 36
72 0.5
64 1.2
70 -0.4
64 21
71
 BEVERLEY DALESMAN D49
   ANWICK UNDAUNTED
   BEVERLEY SUNNY Z43 UK 141158/400079
11/04/2001 0
26 1.3
74 -0.3
65 3
65 3
44 10
77 12
77 0.2
61 1
68 0.1
46 12
77
 
Appendix 8. PowerPoint presentation given to the Sussex Cattle Society at a breeder’s Meeting held at Robertsbridge, Kent, 25th April