December 2025 Changes to Cow Evaluations
- November 25, 2025
In October 2025, Lactanet implemented monthly official evaluations for Canadian females, providing faster updates and more timely access to your genetic data. Phase 2 of this important initiative is now coming in December 2025. With this update, all females will receive only one genetic evaluation, regardless of their milk recording supervision status, ensuring greater consistency and inclusivity across the national herd. This article explores what these changes mean for Canadian females, the impact on top lists, and what to expect moving forward.
Monthly Updates
As a brief refresher, since October 7, 2025, monthly evaluations have been available for Canadian females that either (1) received their first official EBV for production or conformation, (2) official cows that added milk recording data to their evaluation, and (3) active female relatives of these cows. Faster access to the most recent genetic data is thus provided leading to an increased accuracy of selection.
Official vs Management Cow Evaluations
Currently, Lactanet publishes two sets of cow evaluations for production traits: official indexes and management indexes. Official indexes are based on data that meet industry standards and have been available for marketing purposes. Cows enrolled on a “Publishable” milk-recording service and met the requirements have been receiving an official EBV for production traits. Management indexes on the other hand have been for cows in herds without sufficient supervised milk-recording data and have been used to facilitate herd management decisions.
These two indexes made it possible for females to have different values for production traits, but also for LPI and Pro$, depending on the data source. While this met the industry needs, it did lead to some confusion. Moreover, changes to criteria for publishable lactations were made in 2023 to no longer require supervised testing. This major industry shift has provided an opportunity for Lactanet to revise the publication of production genetic evaluations. In doing so, cows will now receive only one production evaluation regardless of the data source. This means that cows with unsupervised test day records can have published EBV values instead of Parent Average (PA) values and top cow lists will thus include a small number of elite cows with unsupervised milk recording data. Official cow EBV for production traits will still require at least two test days of which one is past 60 days in milk, but this will be the same for cows with supervised or unsupervised test day data.
Impact on Top Lists
Using data from the August 2025 genetic evaluation release, Lactanet analyzed how cows from unsupervised herds would influence top lists. Results showed minimal impact on high-ranking positions:
| Breed | Top 100 GLPI Cows | Top 100 Genotyped Cows for Milk | ||
|---|---|---|---|---|
| # Cows with Unsupervised Data |
Highest Ranked |
# Cows with Unsupervised Data |
Highest Ranked |
|
| Holstein | 0 | #141 | 8 | #6 |
| Jersey | 3 | #30 | 4 | #53 |
| Ayrshire | 1 | #61 | 4 | #3 |
| Brown Swiss | 1 | #70 | 4 | #14 |
Similar impacts are expected for the December 2025 top lists, meaning that while cows from unsupervised herds will be included in official evaluations, the overall composition of elite rankings will remain largely unchanged. It is important to remember that these top lists maintain a high level of accuracy given that all cows listed are genomically tested regardless of whether milk sampling is supervised or unsupervised.
This change is only applicable to active females in Canada with unsupervised test day records and therefore no change will be made for females in herds enrolled on “Publishable” milk recording services or for foreign females with a MACE evaluation. Moreover, no changes will be made for males, expect for some Parent Average values for young bulls without a genomic evaluation if they are impacted by female ancestor updates.
Summary
Lactanet is excited to soon mark the completion of a two-phase project aimed at providing more frequent updates and access to the most recent genetic data of females. Since October 2025, monthly genetic evaluations for Canadian females have been a reality and on December 2, 2025, Lactanet will transition to publishing only one set of female production evaluations regardless of the herd’s supervised milk recording status. Moving to one value will reduce confusion and monthly evaluations expand opportunities for cows and heifers to appear in top animal lists.
