How to make a minimum contemporary group to provide effective data to BREEDPLAN

Unlocking benefits no matter the size of your herd

There is a common misconception that only large herds have the scale to make performance recording effective in BREEDPLAN. This is not the case. Smaller herds can achieve significant benefits from Wagyu BREEDPLAN and animal performance data from such herds is useful for all, not just to that herd.

The Basics

The most important concept to understand when considering effective use of data in BREEDPLAN is Contemporary Groups. If you are planning a contemporary group for the purpose of getting carcase data, a contemporary group is considered to be animals of the same sex, born within the same herd within a 60-day period and managed together as one mob. The seven simple requirements for animals to remain in the same contemporary group from birth to slaughter so that their carcase data can be compared;

Seven requirements for animals to remain in the same contemporary group

1 Born in the same herd and within a 60-day period

2 Represent two or more sires

3 Same sex

4 Same birth number (single calves not compared with twins)

5 Same birth status (Natural/AI calves are not compared with ET calves)

6 Have been measured on the same day (eg ; 200-day weight same day, killed on same day)

7 Run under the same conditions from birth to slaughter

Making a minimum effective contemporary group to test sire progeny

The following example assumes a 100% calving rate and equal split of male and female calves with all progeny surviving and the male calves being a contemporary group whole of life plus the female calves being a contemporary group whole of life. Let’s consider the minimum model to create a contemporary group whose data can be used in BREEDPLAN.

Contemporary group size impacts performance record effectiveness

The impact of contemporary group size on the effectiveness of performance is illustrated in Figure 1. The effectiveness of performance is the relative contribution that an individual performance record will have on calculation of EBVs within BREEDPLAN. As illustrated in the graph, the greatest increase in effectiveness is observed going from one animal to two animals in a contemporary group. That is, a record of a single animal is not effective because it can’t be compared to anything.

A performance record in a contemporary group of two is 50% effective, so starting to contribute to useful data as the minimum contemporary group size. Once five to ten animals are represented in a contemporary group, the data is 80% - 90% effective. Having larger contemporary groups continues to increase the effectiveness of data, but the added value diminishes.

Figure 1 refers to the relative impact that an individual performance record will have on contributing to the accuracy of the EBV.

A record of a single animal is not effective because it can’t be compared to anything

Using performance recording to improve the females’ EBVs

An often overlooked fact in genetic improvement is that half of the genetic improvement comes from the cow base of a herd. The cow base of the herd also remains long after you have changed your bulls. Performance recording of the cow and its progeny can significantly affect EBVs and increase the accuracy of EBVs for the cow herd.

The EBVs of the cow herd and their accuracy have an equal outcome on the EBVs of the progeny (compared to the bull used). Performance recording progeny within small contemporary groups to improve EBVs for your cow herd can increase EBV accuracy for your young breeding stock, particularly through use of 100K genomics SNPs. Once a cow has progeny performance recorded, this data contributes to informing the genetic merit of the cow and future progeny. A minimum of 2 animals is required in a contemporary group, but again, four or more animals provides an improved effectiveness of data.

Considerations for capturing and using carcase data in performance recording

The Wagyu industry is unique among the performance recorded breeds in that there are a high volume of cattle processed annually for which slaughter data relating to the final carcase outcome is captured by supply chains. In many instances, accessing this information for the purposes of submitting it to the AWA for use in Wagyu BREEDPLAN to improve EBVs requires arrangements through the supplychain back to the original animal breeder to be agreed.

This is happening on quite a large scale, and contributes data underpinning the genomically-enhanced BREEDPLAN EBVs.

If you are seeking data from supply chain partners for submission to Wagyu BREEDPLAN, in addition to ensuring you can obtain this data, you need to also ensure that the contemporary group structure you have created on-farm is maintained through the supply chain.

For example, if you have a group of 10 animals born in a contemporary group and managed as one group for the purposes of proving two or more young sires, these animals need to be kept in a contemporary group until slaughter. That is, the contemporary group needs to be maintained whole of life with the animals being processed on the same day in the same facility. It does not matter if the animals are mixed with other animals in a feedlot pen or trucked with other animals to slaughter, as long as the animals are all handled the same way.

In BREEDPLAN, the inclusion of carcass data is limited to animals slaughtered at or before 1200 days of age. This age cut-off ensures that the data used for EBV calculations is from animals within a standard age range for more consistent and meaningful comparisons.

Animals must be slaughtered on the same day in the same facility

Research conducted through the Beef CRC in the 1990’s found that the largest impact on meat eating quality and grading outcome, was the variability within and between processors on the day of slaughter.

This means that the transport, lairage, processing and chilling conditions, can have the largest impact on the eating quality and grading outcome. An example of this for Wagyu, is that applying different chilling times, different chilling temperature protocols and having different numbers and arrangement of carcases in a chiller, can greatly impact meat temperature and marbling appearance. Likewise, the temperature at which the cut grading surface is graded, can also impact marbling appearance. These factors can all change day to day within a processing plant and are certainly different between processing plants.

If the contemporary group is split and slaughtered on 2 different days, this will create 2 subgroups and reduce the effectiveness of this data. In this situation, it is vital to report that the groups have been split, because there are likely to be significant differences in the carcase grading conditions used between the grading days and this may negatively impact your BREEDPLAN results if it is not accounted for.