As some of you experienced first-hand, there was a problem with last week’s genomic evaluations published on Tuesday, July 27, by the Council on Dairy Cattle Breeding. The first set of animal evaluations (sent Tuesday morning) received inflated PTAs, especially for the Holstein breed yield and type traits, which in turn reflected inflated values for Net Merit. The problem was addressed as quickly as possible, with corrected results distributed by day-end Tuesday.
Here at CDCB, we strive for excellence, and in this case, we fell short. Our apologies for the inconvenience and confusion that resulted from this error.
As we start this week, we want to assure all stakeholders that this was an isolated incident. We expect a smooth weekly run tomorrow, Tuesday, August 3.
Also, there is no concern of any of this impacting the August 10 triannual evaluations. First, the weekly and triannual evaluations have separate and distinct procedures; hence the specific problem in the July 27 weeklies has no bearing on the triannual evaluation process. Second, the August 10 evaluation is by far the most-tested evaluation CDCB has prepared. One of those important testing mechanisms is an independent validation process through the Dairy Evaluation Review Team (DERT) – a group of industry professionals who provide an impartial and confidential review before all official releases to identify potential problems and reduce the likelihood to send inaccurate predictions.
What happened with the weeklies on July 27?
The genomic predictions were distributed the morning of July 27, as usual for weekly runs. These evaluations are always reviewed by at least two CDCB staff members. Since some changes to the parameters for yield and type traits in Holstein were implemented, the fact that these traits had larger values did not raise concerns initially. CDCB can only validate these evaluations by checking evaluation statistics, since only new animals are included in the weekly evaluations and there is no way to compare them. We failed at recognizing that the higher average evaluations in the weekly were not caused by the changes applied, but by an unexpected inflation in the Direct Genomic Values. As soon as our industry partners raised questions on animals they owned, we began investigating specific cases they provided, and we sent an alert to those that had received the inaccurate evaluations. The detection and resolution of the problem involved all geneticists at CDCB. As soon as we did, we distributed new results at 5:25 pm (Eastern) that same day.
We sincerely thank and appreciate those that alerted us of their concern and showed patience and extra effort to distribute the accurate results. The entire team is, as always, committed to learning, improving, and working each week toward the excellence and confidence that you and all dairy producers deserve.
Please reach out to the CDCB team through Redmine and your routine contacts whenever you have questions or suggestions.