Select Sires

Daughter Pregnancy Rate Evaluation
Transcript of Select Sires' Reproductive Moment Program
on DairyLine Radio, Which Aired Feb. 20, 2003
with Chuck Sattler, vice president,
dairy progeny testing and genetic research,
Select Sires Inc.

Chuck, last week new sire evaluations were released by the Department of Agriculture. Along with this, USDA introduced a new trait that it calls a preliminary trait daughter pregnancy rate. What exactly is DPR?

USDA DPR, or daughter pregnancy rate evaluation, is an attempt to indicate which cows have the genetic ability to give birth and then breed back quickly. Evaluations use DHIA data, and they compare cows based on how many days it takes from the time they freshen to the time they get pregnant again. This data is run through genetic evaluation procedures just like we do with the milk production traits and type traits.

USDA calls this trait preliminary. What does that mean?

It means that the values are new, and we still have things to learn about how to calculate genetic evaluations for these fertility traits. As we go about doing genetic evaluations, we need to make some assumptions on particular things to make the evaluations work. It takes some time and some experience with the new evaluations to build a track record on whether these assumptions are valid or not. For instance, one of the assumptions USDA makes is that each cow in the herd has an equal opportunity to breed back quickly. We do know some herd owners choose to allow high-producing cows a little more time into lactation before they breed them back. So if this happens in very many herds, we could see a bias build in the evaluations that we don’t intend to be there. Another assumption they use is that they have a 250-day open limit that they establish for each cow, to make sure there is quick turn around of the data and we get the information fairly quickly on our bulls and cows. We don’t really have any data to know whether that 250-day limit is appropriate.

And with this being so new, are there cautions that producers should take when looking at the data?

I think producers should use values for individual animals from this new trait very cautiously. Changes may be made with the proofs three months or six months down the road based on the things we learn by using this new information. These changes may cause individual animals to change rank significantly.

Since the USDA has labeled it as preliminary, will producers have access to looking at the data?

USDA has made this information available in their normal procedures along with all the other genetic evaluation traits, and these daughter pregnancy rate values are available on their web site. The Holstein Association and the Jersey Association have decided not to publish the DPR values in their sire directories or on official pedigrees at this time. The Holstein Association will provide this information through their software package, Red Book Plus. You will likely continue to see limited publication of these DPR values until people have a chance to work with them and get comfortable with the evaluation procedures.

So what will this new preliminary trait, called DPR, really mean to producers and for the industry?

Well the bottom line is that management practices are the primary way producers can improve reproductive traits. Genetics only play a very small role in what determines how fertile the cows are. With that said though, as we breed our cattle, we need to do what we can to improve reproduction, but the jury is really still out as to whether this new evaluation from the USDA will help us do that.

Thank you, Chuck. That’s Chuck Sattler, Select Sires’ vice president of dairy progeny testing and genetic research.

Copyright 1996-2003 Select Sires Inc. Last updated 5-Mar-2003.

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