contemporary groups of cattle

What Is A Contemporary Group in Cattle?

by Keaton Dodd

We talk a lot about EPD’s as a tool for progressive seedstock outfits trying to make improvements in their cattle’s performance.

But, if you use EPDs, you want them to be accurate.

There are multiple ways to improve confidence in an EPD like turning in weights, ultrasounding cattle, and keeping up with progeny records.

But, classifying contemporary groups is also a very important – sometimes overlooked – piece of the puzzle when submitting data.

Let’s talk about it a little more…

What is a contemporary group and how does it work?

A contemporary group can be simply defined as a set of cattle that have had the same opportunity to perform.

This would mean same sex, managed similar, as well as exposed to the same environment and feed resources.

By grouping cattle this way, it levels the playing field. We can then compare their performance in a particular trait even though they came from two completely different scenarios. 

Let’s use use an example…


Bull Calf A was born in March, came off good pasture, always had creep, cows were in good shape, and didn’t have to withstand harsher winter weather.

Bull Calf B was born in November, grass was less prevalent, he went without creep, his mother was in poorer body condition, and multiple winter storms impacted herd health.


Obviously, you would expect from the weather alone that bull A could likely have a much higher weaning weight.

The catch is, most of the difference between the two bulls would be credited to an environmental effect and not the individual’s genetic prepotency.

When calculating an EPD, we use what is known as matrices to ensure that the figure we are using is linear and more importantly unbiased for environmental factors.

By using contemporary groups we are mathematically able to eliminate the effect of environmental factors on performance so that we can compare these two bulls fairly.

Would it be possible for Bull B to have a higher growth EPD than Bull A, even if his actual WW was 200 pounds lighter? Yes, maybe.

Once matrices and contemporary groups are factored in, the bad weather is taken out of the equation.

This allows you to truly see what each animal is genetically predisposed to do.

How BRC Uses Contemporary Groups

On the ranch, we try to stay heavily data driven to follow progress and make constant improvements to performance.

To do that, we must ensure we maintain contemporary groups to allow for less of an environmental impact on the values we receive.

For us, the three big factors we consider when grouping cattle are:

  • Gender of the calf
  • If the calf was on creep feed or not
  • What time of year the calf was were born.

Once you consider those 3 factors, we end up with 8 different contemporary groups for the year.

This helps us keep our cattle organized by environment to allow for as little bias in our genetic evaluations as possible.

Also, a couple biological types to consider when properly categorizing your calf crop into appropriate contemporary groups are:

  • Embryo transfer calves vs. natural calves
  • Calves in situation with multiple births (i.e. twins)

For the best and most accurate results when considering these two types, it is best to sort them into their own contemporary groups.

Also, any time some new environmental or management factor is introduced to certain calves, make a new contemporary group code.

Finally, it’s very important to weigh calves in contemporary groups on the same day.

Obviously, not all calves are the same age, but thankfully Digital Beef (ABBA’s registry provider) is so good that it automatically adjusts weights turned in by the animal’s age.

What this means for Brahman breeders…

Ultimately, the ball is in our court to be responsible seedstock breeders. 

The goal is having performance figures we can depend on as tools of improvement within our respective operations. To do that, we must put in the work.

What should you do?

When you turn in your performance data, don’t just turn in blanket default contemporary group. Or, don’t just say all your calves were in the same contemporary group. Turn in the data, and let the system do their work.

When you list multiple contemporary groups, it means better data in, and better data out. It eliminates as many variables as possible.

Thus, the information we put in is better, and we can make accurate decisions based on the statistics we put out.

If you would like to learn more about genetic improvements and BRC’s innovation, contact a member of our team with questions. Or, better yet, we invite you to visit BRC Ranch.

Our New Brahman Breeder Guide is also very helpful to help understand performance information. This is a free guide we offer to any breeder interested in learning more.

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