Publish date: 9.16.25
During the August 2025 Sire Summary, two updates from the Council of Dairy Cattle Breeding (CDCB) were announced, which were the genetic base change for calving traits and the release of a new Holstein Milking Speed. It’s important to be aware of these updates from CDCB and the impact they could have on your dairy. That’s why in this article, we will dive into each update, explaining what it is and what it means for you. Keep reading to learn more.
Genetic Base Change for Calving Traits
What is a genetic base change? All dairy animals with a genetic evaluation or bull proof based on data from the CDCB and Holstein USA are compared to the breed population average, which is better known as the base. Remember, traits are expressed as predicted transmitting abilities (PTAs) relative to this base.
A genetic base is periodically updated to reflect progress in key traits such as milk production, fertility, and health. Essentially, think of a base change like a report card, showing how much genetic progress has been made compared to the previous generation. While the national base change for the U.S. occurred in April of this year, during the August 2025 Sire Summary, CDCB announced the updated base for calving traits, which was originally delayed due to unanticipated results. However, these results have been fully investigated and validated and are now ready to be released.
What does this mean for you?
The new base reflects the improvements in genetics and management, and part of the management changes include a higher percentage of heifer calves being born with the adoption of sexed semen. Remember, calving traits are displayed relative to the phenotypic average for the traits. Below is a table that displays the old and new base averages for Holsteins. As the numbers get closer to zero, you can expect less variation between sires.
| Sire Calving Ease (SCE) | Daughter Calving Ease (DCE) | Sire Stillbirth (SSB) | Daughter Stillbirth (DSB) | |
| April 25 | 2.3 | 2.7 | 6.0 | 6.5 |
| August 25 | 1.4 | 1.8 | 3.6 | 4.5 |
A New Trait for Holsteins: Milking Speed
The second part of the updates from CDCB during the August 2025 Sire Summary was the launch of a new trait for Holsteins, Milking Speed (MSPD). Using data from milking parlors, MSPD is designed to increase efficiency in conventional milking parlors and facilities. PTAs are reported as pounds-per-minute, with breed average at 7.0. MSPD is derived from in-line sensor data, rather than producer scores obtained during the Type classification process, but robot milking data was NOT included. MSPD for all ABS Holsteins can now be found on Bull Search.
Benefits of Milking Speed
- Faster-milking cows can be selected for, allowing more cows to be milked through the parlor in the same period of time, but heavy selection for milking speed has its risks, as higher speeds correlate with higher SCS and mastitis.
- Slower-milking cows can be selected against, improving herd consistency and limiting disruptions to the milking routine.
- Greater parlor throughput is a more efficient use of labor and facilities.
These two updates from CDCB could impact the way you select genetics. Thus, it is important to stay up to date on industry changes and releases. We hope this article helps to inform you of these updates from CDCB and serves as a reminder that we are always here to support you in your genetic selection.
To discuss these updates from CDCB further, contact your ABS Genetic Advisor or complete the form below.
