Multi-Breed Genetic Evaluations EPDs

Be sure to have proper Identification

It is extremely important to have accurate records on your cattle for identification, health, reproduction and production.

Registration papers with the Composite Beef Cattle Registry has fields for cross-referencing identification on animals by various means, tattoo, herd ear tag numbers, RFID, Brand or other noted identification. These cross-references gives more that one way to be able to properly identify an animal.


Estimated Progeny Difference (EPD) is a selection tool that provides estimates of the genetic value of an animal as a parent and are one of the best tools for producers to use to predict the potential performance of future progeny for multiple traits. When comparing two animals, the difference between their EPD predicts the difference in performance of their respective offspring. EPDs are expressed in a measurement of plus or minus for each trait. Interim EPDs will appear on young animals when their performance data has not been incorporated into a genetic evaluation. A Pedigree Estimate (PE) is for animals without any performance data and are based on (breed averages of parents without EPDs) and the EPDs of parents with EPDs.

Historically EPD values could only be directly compared between animals of the same breed. A birth weight EPD for a Simmental bull cannot be compared directly to the birth weight EPD of an Angus bull. These EPD’s can be compared only if the measurement is adjusted for breed composition and hybrid vigor as a result of crossbreeding..

Seedstock producers have been asking for true multi-breed evaluations.

The genetic evaluation model used by the Composite Beef Cattle Registry is truly multi-breed in all aspects, (representing over 70 breeds and approximately 3 million animals), which makes it globally unique.  Our model has extensive central test data, which many breeds do not include in their genetic evaluations.

EPDs are calculated using complex formulas and models, using several pieces of information on an animal in the calculations.  Information  collected to calculate EPDs includes performance data on the animal, (birth, weaning, yearling and other measurements), and pedigree information (sire, dam, grand-sires, great grand-sires, maternal grand-sires, etc), collateral relatives, (bothers and sisters), and progeny (including progeny that are parents themselves).  All performance data that relates to the animal are used and these records are adjusted for factors such as age and sex of the animal and age of the dam.  All adjustment factors allow these performance records to be compared accurately in the calculations.  Superior or inferior mates  influence progeny records.  The statistical analysis used for calculations also takes into account effects of environment (nutrition, climate, geographical location, etc.) that exists between herds.  These environmental factors can be estimated because of the use of artificial insemination which, allows the same bull to be used in numerous herds across the country creating a genetic link between herds.  Animals can be directly compared regardless of their age or origin.


Composite Beef Cattle Registry Trait Descriptions

CED (Calving Ease Direct) – is a genetic prediction of the increase (+) or decrease (-) in percent unassisted calving if the bull is mated with heifers that are an average size and have average calving ability.  The higher the number for this trait means a higher percentage of unassisted births.

BW (Birth Weight) (lbs) – The effect the animal will have on the birth weight of their calves.  Birth Weight is expressed in pounds of birth weight and higher Birth Weight values indicate larger calves which could result in more calving difficulties when bred to heifers.  It is recommended to use low birth weight EPD bulls, especially to breed to heifers.

WW (Weaning Weight) (lbs) – The ability of the animal’s progeny to grow from birth to weaning.  Many commercial producers sell their calves at weaning and are paid by the pound; therefore, a higher value for this trait is more desirable.  This trait may not be as important if a producer is retaining ownership of calves past weaning, except for the effect that this trait as it relates to other growth traits, such as a yearling weight.

PWG (Post Weaning Gain) (lbs) – The prediction of an animals calves ability to grow from weaning to yearling. This number represents the difference in gain expected on average for calves from weaning to yearling.

YW (Yearling Weight) (lbs) – This trait indicates the ability of an animal’s calves to grow from birth to yearling.  Usually a larger value for this trait is better.  This trait is of importance only if a producer is going to keep calves beyond weaning.

SC (Scrotal) (cm) – This trait is used as an indicator of a bull’s ability to transmit scrotal size to his male progeny.  In theory, the larger a bull’s scrotal circumference, a bull’s daughter’s will reach puberty at a younger age and therefore a higher probability the will conceive to calve at two years of age.  This trait is measured in centimetres (cm), with a larger number being more desirable and is only important if males or females will be kept as replacements.

MILK (lbs of calf at weaning) – This trait is the ability of an animal’s daughters to provide their calves with milk and mothering ability.  This trait has a direct impact of energy requirements for milk production, due to the fact that cows that produce more milk require more feed and if sufficient energy needs for this are not met, then it may also affect the ability of the animal to re-breed in a timely manner.  If a producer is in a situation that feed sources are limited, selecting for a lower Milk EPD will be very important.  If a producer is in a terminal mating system, then this trait will have no direct value because no replacements are being kept.

MARB (Marbling) – This trait indicated the ability of an animal’s progeny to deposit fat in the rib eye and is adjusted to a common age (365 days of age)

REA (Rib Eye Area) (square inches) – This trait is the predictor of the difference in progeny rib eye area muscling between the 12th and 13th ribs and is adjusted to a common age (365 days of age).

FAT (mm)–   This trait is measured in millimeters (mm) as the prediction of the fat at the 12th rib of an animal’s progeny when slaughtered, adjusted to a common age (365 days of age).  A lower value is more desirable, but in the case of breeds which are naturally leaner, a higher number for this trait may need to be selected because if an animal’s progeny are too lean the carcass quality is affected.

$W (Weaning Dollar Value) - Many commercial producers sell their calves at weaning. This index utilizes the BW, WW, Milk and mature cow size.  $W is a per head value.

$NR (Net Return Dollar Value) - is  based on a producer retaining ownership thru to harvest with the assumption that heifer to bull ratio is 50-50, retaining 30% of the heifers for replacements and marketing the rest on a grid.  This index utilizes the carcass EPDs and external factors.

ACC% (Accuracy) - value is the amount of relative information used to estimate the EPD.  ACC% values can range from 0.0 to 1.0 with values closer to 1.0 representing a greater reliability in the EPD.  Animals with out any performance data of birth, weaning or yearling weight can have EPDs but they will only be PE (Pedigree Estimates), and are based on breed averages of parents without EPDs and the EPDs of parents with EPDs.