COMMERCIAL CARCASE EBVs
IMPROVING PRODUCTIVITY
AND PROFITABILITY
SIMMENTAL RANKED UK’S #1 CONTINENTAL BREED
FOR AGE AT SLAUGHTER
A bull’s Estimated Breeding Values (EBVs) provide you with a good idea of the genetic potential he will pass on to his calves, and should always be taken into consideration when purchasing stock bulls or choosing AI sires. Although terminal traits such as growth rate and muscle depth are a step in the right direction to producing profitable carcases, they are an indirect and therefore imperfect measure of carcase performance.
Work by Scotland’s Rural College (SRUC), with funding from the Agriculture and Horticulture Development Board (AHDB) and Hybu Cig Cymru (HCC), has led to the publication of the AHDB National Beef Evaluations, a set of five EBVs that are linked to the things commercial farmers get paid for, such as carcase quality and speed of finishing. These are:
- Carcase weight (kg)
- Carcase conformation (EUROP classification)
- Carcase fat class (EUROP classification)
- Days to slaughter (days)
- Average daily carcase gain (kg)
These EBVs are calculated using data from BCMS, processors and breed societies, giving high accuracy figures for bulls that have had progeny slaughtered. For young bulls, EBVs can still be calculated using data from their relatives, such as their parents and grandparents. These figures will get more accurate when their own progeny reach slaughter age. The processor data currently covers 40 per cent of the national kill and almost 3 million carcase records for both purebred and crossbred animals have been used in the latest genetic evaluation.
The heritability tells us what proportion of variation we see in a phenotypic trait is down to genetics. For the new carcase traits, over 40% of variation we see is a result of genetics, so making use of these new EBVs will greatly accelerate improvement in carcase characteristics.
Understanding the new carcase traits
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. They are also highly relevant to beef on dairy sires, with some bulls having the potential to produce a calf that will be much more profitable when put into the beef supply chain.
The carcase EBVs are the first to be released under the umbrella of the AHDB National Beef Evaluations, a growing set of EBVs based on commercial data sources. Further work currently in the pipeline includes the development of EBVs for age at first calving, calving interval, longevity and calf survival, and also EBVs for resistance to bovine tuberculosis.
DAYS TO SLAUGHTER
Definition: An EBV predicting days to slaughter at a given weight and fat class.
Calculated from: Dates of birth and slaughter. These are primarily obtained from records within the BCMS database.
Unit of measurement: Days
Interpretation: Skerrington Superstar has a days to slaughter EBV of -32.67. On average, he will produce progeny that reach slaughter 16.3 days earlier than progeny from a bull with a days to slaughter EBV of 0. High negative values for age at slaughter indicate animals whose progeny reach a given carcase weight faster (ie. in fewer days) than average.
CARCASE WEIGHT
Definition: An EBV predicting carcase weight at a given slaughter age.
Calculated from: Records of cold carcase weight provided by UK processors.
Unit of measurement: Kilogrammes (kg)
Interpretation: Skerrington Superstar has a carcase weight EBV of +5.19. On average, he will produce progeny whose carcases are 2.6kg heavier than progeny from a bull with a carcase weight EBV of 0.
CARCASE CONFORMATION
Definition: An EBV predicting carcase conformation at a given slaughter age.
Calculated from: Records of carcase conformation based on the EUROP classification system, provided by UK processors.
Unit of measurement: Carcase conformation scores converted to a 45 point score. A conformation grade (e.g. R to U) spans about 9 points.
Interpretation: Skerrington Superstar has a carcase conformation EBV of +0.02. On average, he will produce progeny whose carcase conformation is equivalent to that from a bull with a carcase conformation EBV of 0. A bull with a carcase conformation EBV of +9 would produce progeny that have conformation half a grade higher than a bull with a conformation EBV of 0.
CARCASE FAT CLASS
Definition: An EBV predicting carcase fat class at a given slaughter age.
Calculated from: Records of carcase fat class based on the EUROP classification system, provided by UK processors.
Unit of measurement: Fat class scores (ie values 1 to 5H) are converted to a 45 point score. The difference between the main grades is about 9 points.
Interpretation: Skerrington Superstar has a carcase a fat class EBV of 1.18. On average, he will produce progeny that are marginally fatter than progeny from a bull with a fat class EBV of 0. A bull with a fat class EBV of +9 will produce progeny that are half a grade higher (fatter) than a bull with a fat class EBV of 0.
AVERAGE DAILY CARCASE GAIN (ADCG)
Definition: An EBV predicting daily gain in the carcase.
Calculated from: Carcase weight, date of birth and date of slaughter.
Unit of measurement: Kilogrammes (kg)
Interpretation: Skerrington Superstar has an ADCG EBV of +0.04. On average, the daily carcase gain of his progeny will be 0.02kg greater than progeny from a bull with an EBV of 0.
All five EBVs are expressed on two bases, native and continental, so EBVs for Simmental cattle can be compared directly with other continental beef breeds.
What does this mean for Simmentals?
Currently ranked #1 continental breed for age at slaughter
Based on data from the December 2020 evaluation on continental breeds, the Simmental breed ranks number one in terms of average EBV for days to slaughter, with an average EBV of -5.13 days. This average is currently significantly lower than the other continental breeds. The genetic trend for days to slaughter has a shallow downward slope, meaning that Simmental breeders are successfully breeding animals that finish at an earlier age, but there’s still plenty of room for more progress.
We do see high levels of variation in all five traits for all breeds, which combined with the high heritabilities means there is good scope for carcase improvement in every breed. To maintain the current breed advantage in terms of days to slaughter, Simmental breeders should make use of these new EBVs when making selection decisions to help accelerate genetic gain.
Remember: Carcase merit is only one aspect of a profitable beef enterprise. It is important to consider this new data alongside other EBVs when selecting individuals for breeding. For example, animals of high carcase merit should not be chosen to the detriment of health and fertility traits such as calving ease.
Identifying new sources of good genetics
Because the AHDB national beef evaluations are based on millions of commercial carcase records, accurate EBVs are available for a wide range of Simmental cattle.
In the latest run (December 2020), there were 3,902 Simmental bulls with high accuracy (≥80%) carcase traits EBVs. Of these 3,902 bulls, approximately 70% of animals had EBVs for weaning, yearling and finishing weight published on the Breedplan database, and less than 50% had EBVs available for eye muscle area and fat (Table 1). Less than 10% of the bulls had Breedplan EBVs with accuracies of ≥80%.
The AHDB national beef evaluations therefore provide a good opportunity to make better informed decisions on breeding bulls who don’t have enough information within the Breedplan database for them to have high accuracy EBVs published.
| Breedplan Trait | Animals with a published Breedplan EBV | Animals with a published Breedplan EBV >80% | ||
|---|---|---|---|---|
| N | % | N | % | |
| Weaning Weight | 2833 | 72.6% | 247 | 6.3% |
| Yearling Weight | 2833 | 72.6% | 222 | 5.7% |
| Finishing Weight | 2833 | 72.6% | 180 | 4.6% |
| Carcase Weight | 2112 | 54.1% | 60 | 1.5% |
| Eye Muscle Area | 1680 | 43.1% | 4 | 0.1% |
| Fat Depth | 1682 | 43.1% | 44 | 1.1% |
Table 1: The amount of Breedplan data available for 3,902 bulls with high accuracy carcase trait EBVs (≥80%) published via the AHDB national beef evaluations.
Accessing the data
The new EBVs can be accessed via the EGENES website and you can search by pedigree name or ear tag number, at http://ahdbbeef.egenes.co.uk/
Currently ranked #1 continental breed for age at slaughter
Based on data from the December 2020 evaluation on continental breeds, the Simmental breed ranks number one in terms of average EBV for days to slaughter, with an average EBV of -5.13 days. This average is currently significantly lower than the other continental breeds. The genetic trend for days to slaughter has a shallow downward slope, meaning that Simmental breeders are successfully breeding animals that finish at an earlier age, but there’s still plenty of room for more progress.
We do see high levels of variation in all five traits for all breeds, which combined with the high heritabilities means there is good scope for carcase improvement in every breed. To maintain the current breed advantage in terms of days to slaughter, Simmental breeders should make use of these new EBVs when making selection decisions to help accelerate genetic gain.
“Why is the average progeny performance half of the EBV value?”
The EBV is the measure of the genetic merit of the bull. He contributes 50% of his genetics to his progeny, therefore the average progeny performance is 50% of the EBV value.
“Will such small increases in conformation and fat class really make a difference?”
Example shows small benefits (less than half a grade) for conformation and fat class. It’s important to remember that genetic improvement is both cumulative and permanent, so even small improvements will add up over generations to produce higher performing animals.
“How reliable are the new EBVs?”
As with the BREEDPLAN EBVs, the new carcase trait EBVs have an accuracy value associated with them. The higher the accuracy value, the more reliable the result. EBVs are only published for animals where the accuracy for all five traits is over 30%.
How can you help to make these EBVs better?
The production of these EBVs relies on sire details being recorded on passports to be able to identify genetic links between bulls and recorded progeny. In the latest genetic evaluation (December 2020), there were 5 million carcase records that could not be utilised 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
