New EBVs to improve maternal efficiency and productivity

With farmers facing ongoing uncertainties including changes to basic payments and increased pressure to reduce carbon emissions, many suckler farmers are investigating ways to improve the efficiency of their cattle enterprises. Could AHDB's new maternal breed evaluations be the answer? Dr Alex Brown, AHDB's Senior Beef Breeding & Genetics Manager, explains more.

In the past, much of the interest in improving efficiencies has been focused on terminal traits including growth rate and carcase quality. However, with 70% of the cost from suckler beef production, plus emission levels both originating from the suckler cow, farmers are starting to turn their attention to maternal efficiency.

For the past year, AHDB have been working to promote the production of heifers that are efficient, profitable, and fit for the future, under the Maternal Matters campaign. Alongside appropriate management and nutrition, choosing the right genetics for breeding heifer replacements is a key long-term investment, as the benefits are cumulative and permanent.

In 2018, AHDB launched their National Beef Evaluations providing estimated breeding values (EBVs) for five commercial carcase traits in beef cattle, using national data from processors, breed societies and the British Cattle Movement Service (BCMS). Thanks to further research and analysis in conjunction with Scotland's Rural College, it has been possible to leverage further value from routinely recorded BCMS data, and release three new maternal EBVs through the National Beef Evaluation database. These are:

1. Age at first calving
2. Productive lifespan
3. Calf survival

Understanding the new maternal trait EBVs

This set of EBVs is derived directly from commercial data and should therefore be of high interest to commercial producers as well as the pedigree sector. So, as well as being useful when making your own breeding decisions, these EBVs could also be used as a marketing tool when selling stock bulls. These new EBVs provide an opportunity to have a cumulative and permanent impact on suckler herd performance by improving your herd genetics, and they link tightly to key maternal performance indicators (KPls).

Age at first calving

Definition: An EBV predicting the age at which a heifer has her first calf. Selecting for this EBV will produce animals more likely to hold service at a younger age.

Calculated from: Birth and calving dates from BCMS

Unit of measurement: Days

Interpretation: Wedderlie Ebsolvent has an age at first calving EBV of 24.25 days. On average, he will produce progeny who calve 12 days earlier than progeny from a bull with an age at first calving EBV of 0.

KPI: Age at first calving.

Productive lifespan

Definition: An EBV predicting how long females will stay in the breeding herd.

Calculated from: Birth, calving and death dates from BCMS

Unit of measurement: Parities (number of calvings)

Interpretation: Wedderlie Ebsolvent has a productive lifespan EBV of 0.55. Based on a herd of 100 cows, a herd sired by Wedderlie Ebsolvent will have an average of 25 more calvings between them before being replaced, than a herd sired by a bull with a productive lifespan EBV of 0.

KPI: Herd replacement rate

Calf survival

Definition: An EBV predicting the likelihood of tagged calves surviving to 10 months of age.

Calculated from: Birth and death dates from BCMS

Unit of measurement: %

Interpretation: Wedderlie Ebsolvent has a calf survival EBV of 6%. On average, he will produce progeny who are 3% more likely to survive to 10 months of age than progeny from a bull with a calf survival EBV of 0.

KPI: Calves weaned, as a % of females put to the bull.

Remember: The EBV relates to the bull's genetic merit. He contributes 50% of his genetics to his progeny, therefore the average progeny performance is 50% of the EBV value.

What this means for your business

We see high variation for these three traits in all breeds, and as usual the variation within breeds is higher than the variation we see across breeds. The heritability of these new maternal EBVs ranges from 4% (calf survival), to 11 % (age at first calving).

Although the genetic influence on these traits is fairly low, there is still good progress to be made using genetic improvement because these traits have such a high economic value.

All the EBVs available on the National Beef Evaluations database are available to compare across breeds, which is not possible via breed society evaluations.

However, we recommend looking at our EBVs alongside the relevant pedigree breed evaluation, as the two sets of information are complementary to each other.

How to access the data

The new EBVs are hosted alongside EBVs for carcase traits on the AHDB National Beef Evaluations website at www.ahdbbeef. egenes.co.uk, and you can search by pedigree name or ear tag number. You can also access them directly from the animal record page on Breedplan or Signet, depending on your breed of interest.

Developments have also been made to the National Beef Evaluation website, including details of trait definitions, release dates, and both across and within-breed benchmarking tables, as well as a handy reference page listing the pedigree evaluation service providers for each beef breed. Further improvements in the pipeline include a comprehensive FAQ page and an EBV search function.

Driving the data forward through sire recording

The production of these EBVs relies on sire detaiIs being recorded on passports to be able to identify genetic links between bulls and recorded progeny. In the latest genetic evaluation (August 2022), there were over 3 million records that could not be used in the National Beef Evaluation analysis because the sire was not recorded in BCMS, so genetic links could not be made. We are urging farmers to make sure they record known sires when registering animals with BCMS as this is the best way to improve the range and accuracy of these EBVs. As well as recording all known sires for your own herd, please encourage buyers of stock bulls to do the same. Increasing the level of sire recording will allow us to identify genetic links between cattle and improve the accuracy of the results.

For more information on national breed evaluations and beef breeding genetics please visit ahdb.org.uk/national-beef-evaluations

AHDB Beef & Lamb have produced a Suckler Breeding Plan to help farmers record sires used on groups of animals if you don't have computer software. This can be found at ahdb.org.uk/knowledge-library/ suckler-breeding-plan-for-better-returns

Interested in improving the efficiency of your breeding herd? Find out more about AHDB's Maternal Matters campaign at ahdb.org.uk/maternal-matters