This month's official genetic evaluations have been released! Read on for everything you need to know about the run, its changes and new traits, and how to interpret them for use in your herd. |
|
Nearly 95 Million Animals Evaluated |
|
The August evaluations implement updates to the reproductive performance traits (Daughter Pregnancy Rate, Cow Conception Rate, Heifer Conception Rate, and Early First Calving) and introduce three new traits: - First Service to Conception (FSC) for all breeds
- Resistance to Diarrhea (DIA) for Holsteins and Jerseys
- Resistance to Respiratory Problems (RSP) for Holsteins and Jerseys
Highlights of the run: - Variation in DPR, CCR, HCR, and EFC was expected and is visible in this run because of the updates in trait calculations. The amount of variation linked to these modifications rather than simply new daughter data differs across breeds and ages of bulls. More background on the 10 changes implemented is here.
- New traits DIA and RSP performed well when placed in the production environment, but future modifications in the models may be required as data increases rapidly.
- Reminder: Genetic evaluations are statistical predictions based on available data when it is placed in a model. A part of launching new traits is moving the calculations from a research environment to a production environment with an updated dataset. This change is why new traits are not immediately placed in selection indexes but rather evaluated for a minimum of one run first. At launch, one bull’s PTA for RSP has been identified as an outlier. This singular result among thousands was not considered sufficient reason for delaying the trait launch, as it is likely associated with a specific set of conditions that the model does not handle well. The remainder of the results are viewed as informative insight for producers. The CDCB Research and Development team is already investigating to learn more.
- With the introduction of the two new calf traits, Heifer Livability (HLV) also experienced above-average change as the dataset increased and new edits were introduced. This is most visible in general decreases in HLV PTA reliabilities.
- Average values for Net Merit $, Cheese Merit $, Fluid Merit $, Productive Life, and Livability also slightly decreased in August. The average upward shift in reproductive performance trait PTAs for younger animals was expected to have positive effects in these indexes and multi-trait values. However, the gains were balanced by recent trend decreases in production trait values (Fat and Protein) and a readjustment in how the revised traits contribute to Productive Life and Livability.
- Shifts in some haplotype statuses for Holstein Calcium Deficiency (HCD) and Holstein Muscle Weakness (HMW) are due to a large batch of updated female genetic tests submitted by Holstein USA to support improved haplotype estimation.
This run was highly successful and marks a major milestone in improved reproductive performance tools that better account for today’s management practices and the introduction of three new traits! This amount of change in one run has never been attempted before. Additional female insights for herd benchmarking, displayed as the percentile distributions shown below, are available here. |
|
Female Reproductive Performance Traits |
|
A lot has changed on dairy farms in the last two decades, especially when it comes to reproductive technologies and practices – sexed and beef semen, estrus synchronization, individualized voluntary waiting periods, and more. These evolutions in management practices meant we weren’t getting a clear genetic picture in the available selection traits. After two years of review and testing, updates have been made to DPR, CCR, HCR, and EFC, and the new trait FSC has been introduced. |
|
Wondering how each of these traits can be utilized alongside each other? Here's our guidance: |
|
Calfhood disease makes one of the most impactful areas of dairy production even more stressful and expensive. Based on calf heath data shared with the National Cooperator Database, CDCB implemented the first national selection traits to address the two most common calfhood diseases: diarrhea and respiratory problems. PTAs for Resistance to Diarrhea (DIA) and Resistance to Respiratory Problems (RSP) represent the expected resistance, in percentage points, of an animal's offspring to each disease relative to the breed average. Positive values are favorable. These evaluations are currently available for Holsteins and Jerseys. - Heritabilities: 2.6% for DIA, 2.2% for RSP
- Genetic correlations: 0.34 between DIA and RSP, 0.38 between RSP and Heifer Livability, 0.23 between DIA and Heifer Livability
Learn about the data behind DIA and RSP and their applications. |
|
NEW EPISODE TODAY The August episode of The CDCB CowCast is available now! “Recapping the August Evaluations” covers what records were used in the evaluations and highlights how each of the three new traits performed in the run, as well as an overview of how to interpret the revised PTAs for the existing reproductive performance traits. |
|
What emphasis do you put on reproductive traits in your mating decisions? |
|
|
|
Providing premier dairy genetic information services and industry collaboration |
|
4201 Northview Drive Suite 302
Bowie, MD 20716, United States |
|
|
|
