The April 2026 evaluations are now available, with more than 93 million animals evaluated. Most changes reflect expected impacts tied to the annual Breed Base Representation (BBR) update.
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BBR reference population update: The annual update of the BBR reference population resulted in the expected minor impact, outlined in the March CDCB Connection. Affected animals primarily included those with weaker links to the U.S. population, incomplete pedigrees, and/or low-density genotypes. A change was made in the reference population logic as the American Jersey Cattle Association requested the removal of a previously requested rule that excluded older animals (born before 2000) with more than 200 daughters. As a result, all non-Holstein breeds now follow a consistent rule: bulls born before 2000 with more than 200 daughters may have incomplete pedigrees.
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Holstein HCD results: A new submission of 70,784 female gene tests for Holstein Cholesterol Deficiency (HCD) was received from Holstein Association USA and incorporated into the evaluation. This new data improves the accuracy of haplotype calls for HCD. As a result, larger-than-usual status changes are expected, primarily within the female population. We thank HAUSA for this update.
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International (MACE) updates: The number of bulls across all breeds in MACE has decreased due to changes in business rules in France. For the Brown Swiss breed, Switzerland introduced a new calving trait evaluation. Given the number of Swiss animals in the reference population of the U.S. Brown Swiss evaluation, this has a noticeable impact. Additionally, gestation length was introduced in the Swiss system for the first time, resulting in more variation than is typical for an April run.
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