General Questions

The Digest office is in the Canadian Hereford Association offices, contact Jacob by calling 1-888-836-7242 or email

AHA Phone - (816) 842-3757 - see also

THE & Performance

Complete reporting of any trait (not just weights) is important. By only reporting the top half or the few calves you wish to register, they are unfairly biased in the evaluation. Because we don't have information on their entire contemporary group, we can't identify where they fit within the group, and thus the resulting EPDs may not be reflective of the animal's true genetic merit.

Yes. While this information is used in a limited way at present, it is important as it provides insight into the cow's production and may also be used in genetic evaluation.

NO!!! Weights should be taken across the entire herd using a proper scale.

YES!!! If you have complete information on your animals, you are encouraged to submit it. More data will produce more accurate EPDs.

Yes. Contact Val at the CHA office for a password.

Cow weights provide a valuable indication of mature size, are related to maintenance costs and also provide valuable insight into production value, for example percent of body weight weaned.

Cow weights should be taken at weaning time. While it may not be possible to weigh cows on the exact day of weaning, cows should be weighed as close to weaning as possible.

Management groups are animals that have been managed together, or given the same environment and opportunity to perform. These groups are important because they allow us to make more direct comparisons between animals. If animals were in the same environment, the only differences in their performance should be due to genetics, and the influence of their dam. This is key to genetic evaluation.

A management group consists of animals that are managed together. A contemporary group is a more refined management group that also includes factors such as sex, and age in order to make comparisons.


Calves that are sick or injured should be grouped separately from healthy calves. Because of illness or injury it is unfair to compare these calves directly with others as they have not had equal opportunity to perform.

The evaluation applies an age of dam adjustment to account for the difference in performance of calves from first calf heifers vs. mature cows. If however, heifers were managed differently up to calving you may wish to assign them a separate management group.

Because of the impact of in utero environment a twin cannot be directly compared to single born calves. Data from twins is edited out of the genetic evaluation for the same reasons.

The birth contemporary group is determined by the calving group code, the sex of the calf, and a 60 day age range.

Birth weights should be taken within 48 hours of birth using a proper scale (not a tape or a guess)

Last 5 years: Female 89.6 and Male 95.0

There could be several reasons. Perhaps the calf is outside the accepted age ranges, or is in a group that is too small to index the calf.

Because of the special management show cattle receive they cannot be compared with the rest of the herd. For example, a single show bull cannot be directly compared to bulls left on grass over the summer as he has had extra nutrition and opportunity to perform. If you have a string of show calves of the same sex and similar age that have been treated the same, they can be indexed.

Because animals have an aging pattern, we try to weigh animals at a consistent stage in the growth curve. This allows us to make more accurate adjustments for comparison of animals and calculation of adjusted weights and indexes.

140 - 270 days of age

301 – 530 days of age

The first number is the breeder-assigned management group. The second is the calculated contemporary group identifier.

WPDA is calculated by taking the animal's weight and dividing by its age in days.

ADG is calculated by subtracting the two weights and dividing by the number of days. For example: ADG to weaning = weaning weight – birth weight / weaning date – birth date. ADG weaning to yearling = yearling weight – weaning weight / yearling date – weaning date.

Because each animal is a cumulative total of its genetics interacting with its environment over its lifetime, it is important to separate groups based on pre-weaning environment.

Yearling weights provide valuable information about growth patterns, post weaning growth and mature size. As well, this information is valuable in prediction of carcass merit for traits such as yield and carcass weight.

Ultrasounding yearling animals is vital to measuring genetic merit for carcass characteristics. By ultrasounding yearling animals we can rapidly get an estimate of relative genetic merit (carcass EPDs) for traits of intramuscular fat (marbling), rib-eye area and backfat. This allows us to assess our position and make positive changes to carcass merit. (Ultrasound Guidelines Council) (Centralized Ultrasound Processing Lab)

Contact the CHA
5160 Skyline Way NE
Calgary, AB T2E 6V1
Phone: 1-888-836-7242
Fax: 1-888-824-2329

Disposal codes provide us information about why animals have left the herd. This is key to assessing fertility, longevity, and identifying specific weaknesses and strengths in various bloodlines.

Select the disposal code that best matches the reason for culling or disposing of the animal. While disposal codes may lack some specific detail, they are attempting to identify broader categorical reasons for animals leaving the herd.



EPDs are calculated using performance information. If you wish to receive EPDs on your cattle, you must participate in the THE program and submit information such as birth weight, weaning weight and yearling weight. If you choose to participate it is important to submit information on all calves, not just those you want EPDs for.

The effects of the recipient dam on calf performance makes embryo calves difficult to include in genetic evaluation. EPDs on these calves will be based on records from relatives, and as they get older, on progeny records.

First, you must submit information through the THE program on the calf and its contemporaries. It is also possible that the animal's record was edited out for a number of reasons.

A pedigree estimate EPD is calculated using the average of the Sire and Dam EPDs. It is a preliminary measure of genetic merit of the animal before we have had the opportunity to use the animal's own information in genetic evaluation.

Accuracy is a measure of how much information was available when the EPD was calculated. Typically, an animal with its' own record and no progeny will have an accuracy of around 0.30. As we add information on progeny and other relatives, this measure will tend to go up. (Sire Summary – Accuracy description)

Accuracy is important because it tells us how much an EPD is likely to change. When we have little information on an animal's genetics, it is possible that the EPD could change a lot as we learn more about it. Animals with high accuracy mean that we have a lot of information about them and their EPDs are unlikely to change.

EPDs are calculated using all available information on an animal. This includes its own record, records on its relatives and records on progeny. As we continually gather more information, we know more about the animal's genetics and thus the EPDs may change.

It is difficult to say. Because environment affects performance the EPDs cannot predict the actual birth weight of an animal. If you were to use a bull with a BW EPD of 0.0 we would expect the calves to weigh 5 pounds less than those from a bull with EPD of 5.0. In one herd this may mean 95 pounds vs. 100, or 80 pounds vs. 85

Calving ease is a measure of the ability of an animal to be born without assistance. Maternal calving ease is a measure of an animal's daughters' ability to calve without assistance. For example if we are keeping replacement females from a sire, we are first interested in their being born without help (CE) and then eventually entering the cowherd and calving without help (MCE).

The Milk EPD is a measure of maternal ability. Various research projects throughout North America and the world have shown that selection on Milk EPD will result in increased volume of milk production.

A Milk EPD is a prediction of how an animal's offspring will perform in terms of milk production. Information from a sire's daughters and other relatives will result in the production of a milk EPD. Remember, even though a sire cannot express milk production, he can pass on milk production genes to his daughters.

There may be a variety of reasons for a milk EPD being low. A Milk EPD is a measure of the environment a bull's daughters provide to their calves. If their calves are lighter than average then the bull's milk EPD may be low.

Remember, an EPD predicts progeny performance. Her EPD will be based on offspring and records from other relatives. Just as we like to look at a bull's mother before we buy him as he can pass on maternal genetics, the same is true in reverse. A cow can pass on genetics for scrotal circumference.

Multi-trait analysis means that we can accurately calculate EPDs using information from many traits at once and their interrelationship with other traits. For example, we know that several genes that control growth to weaning also impact post weaning growth. Thus we can use weaning weight information to more accurately predict genetic merit for yearling weight.

MPI or Maternal Productivity Index is the first selection index for Hereford cattle in North America. It is a single number that combines information on cow weight, stayability, milk production and growth genetics based on their relative economic impact. It allows for ease of selection by the commercial industry for overall maternal merit. (MPI description)

The CHA has a variety of publications including a sire summary and other brochures that can be provided to your customers. Basically EPDs use all of the performance information available to predict an animal's relative merit. It is like having a copy of the pedigree and then driving around all of North America to look at a sire's progeny before formulating an opinion on the sire. (Junior sheets, articles)

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