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Hosted by members of the University of Minnesota Extension Beef and Dairy Teams, The Moos Room discusses relevant topics to help beef and dairy producers be more successful. The information is evidence-based and presented as an informal conversation between the hosts and guests.
Welcome to the Moos Room. It's actually a nice day, Western Minnesota today. Not too much heat stress. The temperatures have been cooling a little bit. Actually, in the morning it's been 50 degrees Fahrenheit, so it's been nice. Maybe a little bit hot this week again, but maybe the heat stress is kind of going away, but I'm sure it will be back.
But I can only be thankful for that. Just trying to get ready here for our county fair. My kids showing cattle, obviously showing for anybody's been quite important. Just depends on whether you like the show cow world or not. I've been showing since I was, I don't know, a teenager, and I looked in the pasture today for my kids.
We were clipping and washing, and there's four breeds out there. We have Holsteins, Jerseys, Guernseys, and Brown Swiss. So it's kind of interesting to see all of these breeds. But alas, the show cow world is very different from the production world, and I wanted to talk a little bit about some genetic traits that are coming out.
If you haven't heard, maybe this is something new for you, but US Council on Dairy Cattle Breeding is gonna release some new traits for animals, actually Tuesday, August 11th, so in a couple days from now. And I just wanted to talk a little bit about those, kind of give you an overview about what they are from a calf perspective, and then there's some new fertility traits out there as well, and give you my perspective.
I'm not sure that I necessarily agree with one of them, uh, anymore. But let's give you a rundown on what those traits are and how you might use them in your farm. So there's two calf traits that are gonna start addressing calf wellness through the US system. Now, this is not DWP or the Zoetis calf wellness traits.
This is the US, uh, Council on Dairy Cattle Breeding's calf traits. I think there's been some calf wellness traits with Zoetis for a few years, uh, from the herds that they've worked with. But this was really done on a national level, and there's genetic evaluations for calfhood resistance to respiratory problems and resistance to diarrhea.
And they're now gonna be provided for Holstein and Jersey males and females. And so these evaluations are gonna be expressed as a percentage points of resistance above or below a breed average. So why, why now? Why introduce these calf traits now? Well, obviously re-raising replacement heifers is very costly in the dairy industry, and really there's cost associated with diarrhea and respiratory problems.
So now really dairy farmers might have a new genetic selection tool to help improve the resistance of these two common health challenges in dairy heifers. And really these health challenges can- Can have lasting effects on cow productivity, livability, and health later in life. So the first one is respiratory disease.
So this is a PTA or predicted transmitting ability, which represents the expected resistance of an animal's offspring to calfhood respiratory problems in a herd. The diarrhea PTA represents the expected resistance of an animal's offspring to calfhood diarrhea or scours
The diarrhea PTA represents the expected resistance of an animal's offspring to calfhood diarrhea or scours in a herd. So in both of these traits, larger positive values are more favorable, which indicate increased resistance
If you think about it, the estimated heritability is about two point six for diarrhea and two point two for respiratory disease. So small heritabilities, although it indicates we may be able to make some genetic progress with selecting for these traits as well, but like most of the other health traits, it's quite low So where did this data actually come from?
So it comes from US Council on Dairy Cattle Breeding. Most of the records were from the East Coast, and there were over 250,000 records for diarrhea and almost a million for respiratory disease that were scored in the US. So we've talked about health recording in the US, and I think producers can help continue to improve these calf traits and other traits, health traits, by recording a lot of this information, and I think it's essential.
And we've talked about health recording, and we record every single health event into our dairy management software, and you can do that in Dart software or Dairy Comp or BovaSync or whatever herd management software program you're doing. And I think it's pretty important to continue to collect that information
So how do we interpret these traits? Well, if you have, say, two Holstein bulls, one has a PTA for diarrhea of zero, the other one has a PTA of plus one, that means that On average, you have about a one percent increase in resistance to diarrhea, and the same with respiratory. So obviously, smaller results that you can see for some of these calfhood traits, but I think it's pretty im-important.
Now, that's average. Obviously, if you look at bulls, there's a lot of variation in bulls, especially Holstein and Jersey. So if you look at active AI bulls, Holstein range from minus five to plus two, Jersey minus seven to plus three and a half. So a large range in there, especially when you go from minus seven to plus four.
The genomic bulls are about the same, and so you have this large range and variability in these sires
But as of right now, these new calf traits are not going to be incorporated into lifetime net merit, and it's really anticipated these calf health traits would be incorporated in the next net merit revision. And obviously, there's gonna be lots more work with these new traits, uh, with the calves, and obviously, hopefully they'll collect more data as the farms start using some of these, uh, information, and we can just get a lot better evaluations on these calf traits
So what about fertility? So there's a lot of updated fertility traits that are happening, and there's one actually new fertility trait that's going through. So since 2003, the US genetic system has produced traits with female reproductive performance. And they decided to look at some of these traits again in 2024 and revise them, and they're gonna be available for Ayrshire, Brown Swiss, Guernsey, Holstein, Jersey, Shorthorn males and females in August
So let's talk a little bit about the fertility traits and, and why they might have done this So these reproductive traits were first available in 2003, and that was with DPR And we'll talk about what the traits are in a second. And then six years later, cow conception rate and heifer conception rate were added.
And in 2019, early first calving was introduced. So really over the 20 years or a little more than 20 years, obviously reproductive management in herds has changed substantially from synchronization programs, uh, sex semen use is quite high now, beef semen use, a lot of automated sensor systems. And there's been a lot of variation in voluntary waiting periods, which all really impact the cow's reproductive performance
So they decided to look at these traits again because there were a lot of seasonal fluctuations between evaluations. There were many large changes between December and the April evaluations. Young bulls were declining a lot in their subsequent evaluations, so they had high PTAs and a few evaluations later they were negative.
And genetic trends were really moving in unexpected directions for some of these new traits on farms. So they went through an extensive review in twenty fourteen and decided to enhance these reproductive traits So what are they? Well, DPR, so that was the first one they introduced. So that predicts the percentage of non-pregnant cows that will become pregnant in each 21-day cycle compared to the breed base.
So DPR is calculated as a function of days open and the voluntary waiting period. And that was why they decided to change this a lot is because the voluntary waiting period in many herds has changed. Maybe 25 years ago it was 50 days or 55 days. Well, now it's a lot later. Some days it may be 70 days or more, depending on the herd.
Every herd is gonna be different So days open in DPR is calculated as the number of days from calving to conception, and then it's transformed into a pregnancy rate using the voluntary waiting period
Cow conception rate predicts a lactating cow's ability to conceive. So it's the proportion of inseminations that result in pregnancy for an individual cow from the first seven inseminations. Heifer conception rate, the same as cow conception rate. It predicts a heifer's ability to conceive. Early first calving, which was introduced in twenty nineteen, is the number of days between a heifer's birth and her first calving.
So it predicts the ability of a female's offspring age at first calving. We've seen age at first calving decrease a lot in, in dairy herds in the US. And there's a new trait, and that's first service to conception. So this predicts a cow's ability to conceive, and it's expressed in days. So it's a new trait, and it predicts the expected difference in days from first service to conception in an animal's daughter's relative to a breed base.
So basically, from first service, so you would say days to first breeding to conception. And it's not a function of voluntary waiting period, so it really accounts for the individual cow management independent of the voluntary waiting period. So if you start breeding cows at seventy days and they conceive at maybe a hundred and twenty days, that's first service to conception.
Doesn't matter what the voluntary waiting period is in a herd
So what might some of these applications be? So if you think about daughter pregnancy rate, it's really informational for producers who use voluntary waiting period on a herd level and want cows to cycle, get bred, and become pregnant quickly regardless of the number of services. So cow conception rate, and I look at cow conception rate when I'm selecting bulls most definitely.
So that's really for farmers who want to improve conception rate success per service, since this trait really reflects how many inseminations are needed. And first service to conception is useful for producers who select voluntary waiting periods on a cow basis and want cows to get pregnant as quickly as possible after the first breeding without focusing on how many services it takes.
So one of the traits uses voluntary waiting period, the other one does not
So now the model enhancements, the DPR uses herd year and lactation group-specific voluntary waiting periods, so it's not necessarily assigning one voluntary waiting period for the whole herd. And cow conception rate and heifer conception rate are using service sire breed, so it might account for different breeds, whether using dairy or beef, what mating type it was done, and kind of includes cows that are short cycling
So some of the key findings that they use. So it shows that genetic trends reflect on-farm observations. So it says that genetic trends of these traits now align with producer-observed reproductive performance and selection pre- pressures. Now, this is where I kind of have a little bit of questions regarding this, because if you look at The old system, so what we're on today before August 11th of 2026, it shows that the DPR is going down in PTA for bulls and has had a steady decline since 2000 to-- in the last twenty-five years.
However, in the revised system, now the bulls are gonna be positive. So actually it's been increasing since 2000 to 2025, and now the bulls are gonna be positive on average So I'm not sure really what's going on. It shows this in cow conception rate as well, where the old system showed cow conception rate was declining, and actually since about twenty ten it's actually been increasing.
So I don't know. I'd like to do some more exploring of this. I think there's a lot of management factors going into this, especially with DPR, because now when I look at the graphs, and you can look at these online as well
It shows that DPR hasn't been decreasing across the 25 years. It's actually been increasing across the 25 years. So I'm really not sure what's going on. I think there's maybe s- a lot more management going into this, whether it's sync programs, sex semen, sensor systems, and, you know, they tried to separate out some of these management effects or noise is what we call that in the data, to really look at the true genetic progress herds have achieved.
But I don't know. I'm really skeptical because now all of a sudden it shows, you know, oh, well, DPR has been improving across the 25 years and actually hasn't been decreasing. So it's gonna be a little different looking at some of these bulls and cows especially that maybe now they're gonna be positive for DPR instead of being negative for DPR.
So it's gonna be a little education to look at some of those bulls and go, "Well, what happened?" Because it was negative before, and now he's all of a sudden positive. So we're gonna see what happens on proof day and see how much some of these bulls maybe have changed across time. We'll, we'll see. We'll see where that goes and, and how that actually might look
Especially the young bulls now should behave a little bit more regularly. It will maybe equalize some of these fluctuations where you have positive and then they go really negative. So it will reduce this negative trend observed for a majority of the bulls. You know, whether obviously nobody likes it when the bulls they select today in the next proof or two proofs from now are negative.
So it's gonna be interesting to see what happens there. And most of it is for DPR and like you said, I, you know, I don't know how many farms are still using DPR and, and I look at DPR, but it's been kind of disappointing lately because everything is negative and so I tend to use cow conception rate a little bit more, uh, especially.
The proven bulls are gonna remain stable, so not much will change with the older proven bulls as far as these different traits. And the trend across time will show less variation, so it kind of reflects the genetic merit of the bulls across time. And obviously it shows a much clearer upward trend and smaller average differences among the evaluations.
So it's gonna be interesting to see, um, what really is going on and how that might work. Because now the DPR calculation's gonna include a variable that accounts for voluntary waiting period by specific herd years and lactation groups, whereas the previous formula assumed a fifty-day voluntary waiting period.
So it kind of updates that. So that's a good thing that they're updating the voluntary waiting period, but it's changed the DPR values quite a, a lot
And this new first service to conception, that might be an interesting trait to really look at to see, uh, how that works for, uh, pregnancy and being able to get animals pregnant
So some of the bulls you're gonna see change as far as net merit and how that might look with DPR. So it'll be interesting to really see what's gonna happen with these new fertility traits and how they change for different bulls and what people may observe or may not observe in some of these animals.
So with that, hopefully you learned a little bit and maybe check out the new genetic evaluations that are gonna come out in a few days and really see what happens. You know, check out some bulls. I'll, I'll be curious. I'll be looking at some of the bulls that I've used here in our herd, Holsteins and Jerseys and, and other breeds, and kind of compare how they change from a DPR, cow conception rate, heifer conception rate standpoint, and really see what's going on.
I'm interested to see the calf hood traits on these bulls as well. So it's gonna be interesting. It'll be interesting, and I'm sure there'll be a lot of education done on these new proofs to see what happens, and people might have quite a few questions So with that, I think we'll leave you today, and if you have any comments, questions, or scathing rebuttals, feel free to contact me at The Moose Room.
That's T-H-E M-O-O-S-R-O-O-M @umn.edu, or find us on the web, University of Minnesota Livestock Extension, or University of Minnesota WCROC Dairy. And with that, I hope you have a good week. I'll be at the county fair. Bye.