Data Reporting: Getting Back to the Basics

GW GW DATA BULLETIN

Data Reporting: Getting Back to the Basics

by Tonya Amen

In our technology-driven world of the 21st century, cattle breeders have a plethora of tools in the toolbox for genetic selection, and often the discussion of some of the more modern technologies overshadows the basics. So, this month, we want to focus on the basics, to make sure we are still getting them right.

There is still tremendous power in performance data reporting. In fact, reporting that data completely and accurately is more important than ever.

One of the greatest sources of error in performance data reporting is improper contemporary grouping. Keep in mind that the purpose of submitting performance data on seedstock is to evaluate the genetic difference between individuals. That said, we need to be sure that the data submitted is as free from environment and management noise as possible. This is where contemporary group (CG) reporting comes into play.

A contemporary group is simply a group of cattle that have had the same opportunity to express their genetic potential. This means animals of the same sex, born and raised at the same place and treated the same way get reported together. It also means the dams of all calves in the CG were treated the same way..

One potential issue in contemporary grouping is grouping animals that have had different planes of nutrition. This difference could be due to different pasture conditions from one location to another or supplemental feeding of some animals and not others. Animals from different pastures should be in different CGs. Also, if any animal or its dam received supplemental feed or creep feed, that was not offered to the whole group, they need to be in a separate CG. Below are some other important factors to keep in mind when reporting CG. Management and feed codes are used to denote those animals who were managed alike (same pasture) or different (creep vs noncreep or treated for illness, etc).

Table 1: Factors for reporting CG

In addition to grouping the animals correctly, another important factor is the complete reporting of the entire group. While there is the temptation to only report “the best”, succumbing to this temptation can have negative consequences.

For example, in the below table, the adjusted weaning weights of 10 animals are listed in order from lightest to heaviest. The average weaning weight for the entire group is about 716 pounds, while the average of the heaviest five is about 752 pounds. It seems like reporting an average weaning weight of 752 would be better than 716, right? Not so fast! Let’s dig a little deeper.

The middle columns in Table 2 show the deviation from group average and ratio for each animal if all 10 animals are reported. The last two columns show the deviations from average and ratio if only the “best” five are reported. Incomplete reporting has negatively impacted the ratio of every single animal in the group, which directly translates to the EPD computation of that animal as well as the sire and dam. So, while a heavier group average might be great for coffee shop bragging, the incomplete reporting has negatively impacted the ultimate genetic prediction results for the entire group –which is nothing to brag about.

Table 2. Complete vs Incomplete Weight reporting.

While we live in a technology-driven world, it’s still important to remember that the basics matter now more than ever, because it’s the basic data that gets used to develop and train the technology (like genomics). As we move into the season of reporting data, let’s remember that eventually an animal’s EPD and genomics will be derived from the data we collect and report. This calving season, let’s be sure to refresh diligence in reporting correctly collected, correctly grouped, and complete data. D