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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. Back from ADSA in Milwaukee, Wisconsin. It was a great time. Learned a lot about lots of different research on calves to grazing, genetics, got to meet with lots of different colleagues. It was a good time learning about lots of things related to dairy production systems and came back with lots of good ideas, as usual.
But I wanted to kinda give you an idea on some of the interesting studies that I thought were, were kind of interesting and from a calf perspective, so we're gonna talk about calves today a little bit. As usual, we like to talk about calves and management, colostrum management, and I saw a couple studies there related to colostrum management on calves and beef-on-dairy crossbreds.
Another study was on weaning of those beef-on-dairy crosses, and then kind of look at some other, couple other calf studies that happened along the ways So the first one was basically colostrum feeding practices on beef-on-dairy crossbred calves and this was from Heather Schlesser at University of Wisconsin in Extension, and she's out of Wausau.
So this study, basically they wanted to compare and identify trends in colostrum feeding practices among dairy heifer calves that were retained on farm, beef-on-dairy calves, and then non-retained calves, so calves that are left, get sold, go somewhere else from the farm. So this study looked at 27 Wisconsin dairy farms and almost 3,000 calves across all of these farms and they looked at some management practices
So basically if you look at herd size, so we'll kind of break this down by herd size. So there were six small herds in the study, so that's less than 100 cows. 10 herds that were 100 to 600 cows, and 11 herds that were 600 cows and greater. So kind of a wide range of farms. Obviously a l- quite a few more farms over 100 cows In the study, there were 1,480 calves that were retained
So in this study, there were fourteen hundred and eighty-two calves that were retained on farm, twelve hundred and eighteen beef on dairy crossbred calves, and about two hundred and seventy calves that were not retained on farm. So they broke it down by quite a few things. So if you look at colostrum feeding method, so they were either bottle-fed, nursed, or tube-fed.
So if you look at the small farms, majority of those calves raised on those small farms are bottle-fed colostrum. Eighty-six to ninety-seven percent are bottle-fed. There's a few beef on dairy ones that are n- allowed to nurse on the dam. There's a few from the retained farms as well. Not very many small farms are tubing calves that they're retaining, but for the most part, bottle-fed colostrum.
Come to the medium farms, they're seventy-seven percent, seventy-five percent are bottle-fed, and about twenty-three to twenty-six percent of retained calves, beef on dairy, non-retained are tubed. And you go to the large farms If you look at the retained calves, so the dairy calves that they're retaining on farm, 83% were tubed, 17% were bottle-fed.
Now if we move to the beef-on-dairy cross calves and the non-retained calves, 98% tube-fed. So these beef-on-dairy crosses, majority of them are being tube-fed colostrum So what about the colostrum source? So they looked at maternal colostrum, pooled colostrum, or another dam. On the small farms, 80 to 100%
of the colostrum source is basically pooled. The beef on dairy cross calves, 79% were pooled colostrum, 20% were from maternal or from the dam. The same with their non-retained calves. Now if you go to the medium-sized farms, so those from 100 to 600 cows, it's kind of variable all over. Some are fed colostrum from the maternal, from the dam, some are fed pooled, and 17 to 26% are fed from another dam.
So the beef on dairy cross calves 33% are fed from their maternal, from their dam. If you go to the large farms, we look at lit- retained calves, about a third of each maternal pooled or another dam. The beef on dairy crosses, 66% maternal colostrum, 30% another dam. Non-retained calves, another dam, not much from the maternal
So if we look at the percentage of each calf receiving first and second colostrum feeding. So the calves that are retained on farm, 100% are getting the first feeding, 92% are getting that second colostrum feeding. Beef on dairy crosses 100% get a first feeding, 52% a second feeding of colostrum. The same with the non-retained calves.
About 100% get first fed, 60% get a second feeding of colostrum. So for the most part, we're all getting at least a first feeding of colostrum into these calves So they looked at the mean time to first colostrum feeding by calf status. So the retained heifers, hour and 14 minutes. Beef on dairy, hour and 21 minutes.
So about the same, no difference between those. The calves that were not retained on farm, hour and 44 minutes. So 20 to 30 minutes longer to get that first feeding colostrum in if they knew that calves were not being retained on farm. The volume of colostrum, now here's a little bit of difference. So the retained heifers, heifers that we're gonna keep on farm, average mean colostrum 3.9 liters.
Beef on dairy crosses 3.7 liters. The non-retained calves, 3.6 liters. So if we know we're gonna retain heifers on farm, they're getting more colostrum than even the beef on dairy, and the non-retained calves are getting less The quality of that colostrum retained calves 28 on a Brix quality scale, beef on dairy 22, non-retained calves 24.
So the heifers that we know we're gonna retain on farm have higher quality colostrum going into them compared to the beef on dairy and non-retained calves. Now there's nothing wrong with 22 and 24 colostrum levels. They're just getting less quality colostrum compared to those calves that are being retained
So in conclusion, what did this study find? Well, overall, calves that were designated for retention in the herd, they received better colostrum management
And the beef on dairy cross calves and these non-retained calves, well, they f- kind of fell below the standards of the retained calves. So their management differed a lot, and most of that was they were fed less colostrum, the colostrum quality wasn't quite as good, and it took longer to feed them But the beef on dairy cross calves, they received more colostrum and were fed faster than the non-retained calves
And basically, the authors here concluded that these findings kind of highlight some opportunities to promote improvement in colostrum management, especially for beef-on-dairy cross calves. And by having better colostrum management, we might gain some economic value to these calves, especially into the future So kind of an interesting study there on some beef on dairy crosses and colostrum management.
Quite interesting So what about another beef on dairy cross study? So this one looked at weaning protocols and growth of Holstein and Angus-Holstein crossbred calves. So these are Angus beef on dairy crosses. And this study was done out of North Carolina State University So they looked at calves and were looking at weaning protocols.
So they had a control, and that was weaned at 65 days of age, so basically nine weeks. And then they had a weaning protocol where calves were weaned after they had starter intake of 2.8 kilograms for three consecutive days
So that's about six pounds of starter for three consecutive days. So one weaned specifically at nine weeks, the other one was weaned off of grain intake and when they were consuming six pounds of grain for three consecutive days
So what did this study find?
So they had Holstein and Angus Holsteins both in the control and both in the weaning by starter intake Well, they didn't necessarily find a lot of differences, at least between the breeds. However, calves that were on the control, so weaned at nine weeks, had more milk intake and less starter intake compared to the calves that were weaned by six pounds of grain.
So the total intake for these calves was greater, obviously, because of more starter intake. So they just consumed more starter. So if you're weaning by starter intake, they're gonna eat more starter, especially post-weaning. So they looked at weaning through
115 days of age, and those calves just consumed about two kilos or roughly four and a half pounds more starter intake So what about average daily gain? Calves, uh, pre-weaning, they didn't find any difference in treatments, whether control or weaned by starter intake. Didn't find any difference between Holsteins or the beef and dairy cross calves.
Now post-weaning, interesting. Average daily gain much greater for the calves. In some cases, almost double average daily gain for those calves that were weaned off of starter intake compared to calves that were just weaned at nine weeks of age. But if you look at kind of a feed efficiency standpoint, overall gain to feed, no significant difference at all between calves that were weaned at just nine weeks or weaned based on starter intake
Basically, the calves that were weaned on starter intake actually were weaned much later, 30 days later, so another month compared to the calves that were just weaned at nine weeks. Some of them, so 97 to 106 days. But overall gain to feed, no difference. Post-weaning gain, yes, those calves that were on starter certainly consumed more starter, more solid feed intake at that time compared to the calves that were just weaned at nine weeks
So basically, what are the conclusions of this study? So the intake calves, so calves that were weaned based off intake, had greater overall average daily gain. They had greater feed efficiency post-weaning. They had greater weaning weights basically because they were on starter intake, longer days on feed
So here we didn't necessarily find a lot of differences between the Holsteins and the Angus-Holstein cross calves, but basically it showed that they can be reared on an automated feeder, and we're gonna do that, some of that research this fall as well And obviously there needs to be a lot more research on these beef on dairy crossbred calves reared in auto feeders and really looking at weaning and starter intake and milk intake, and actually looking at quite a lot of feed efficiency.
So kind of interesting on that beef on dairy cross study Kind of look at a couple other studies quick here. Another one looked at pre-weaning growth and health outcomes
In another study that actually we did here at Minnesota, so I have sensors on my calves and I wanted to look at them through 150 days of age. I know I looked at them prior to that in nine weeks of age, but I wanted to carry it out a little more and see what happened at 150 days of age for Holstein calves and our crossbred calves.
I had almost 12,000 sensor observations, so we kinda looked at birth between 250 days and really wanted to kind of see if there were some differences in breed groups and then really what happened with rumination
Basically all of these calves were fed 10 liters of milk, raised on an automatic calf feeder or outside in groups of 10. Basically the results were
Some of our crossbred calves, so our ones sired by rumen Montbeliard, had greater rumination than Holstein calves. They also had greater eating behavior than Holstein calves
And greater activity levels. So these crossbreds are far more active, ruminating more, eating more. Now, I've debated this before, is rumination actually happening at one week of age? No, it's not. I think what is rumination? Basically eating behavior, drinking behavior for these calves, at least in the first few weeks of life.
You know, I looked at rumination with age. Rumination increased about 60 minutes per day in the first two weeks of life, and by the time the last two weeks, so close to 150 days, they were at 400 minutes a day, and that's post-weaning. So are they really ruminating 60 minutes a day when they're two weeks of age?
No. They're, they're drinking milk. These calves were getting some starter, but they're certainly not ruminating 'cause the stomach just isn't developed yet. So it's picking up feeding behaviors, uh, in s- in classifying them as, as rumination. But as the calves get older, obviously they start eating more solid feed, more grain, then they start picking up some of that rumination behavior, and by the time they're 150 days of age, sure, they're definitely ruminating, uh, then as well
But basically in the end it showed that these ear tag sensors captured meaningful behavioral differences among some of the breed groups and obviously rumination sharply increased with calf age, which really supports the value of some precision technology in calf management
And the last study I wanted to talk a little bit about and just give you an idea about what's happening is looking at colostrum yield and colostrum composition in dairy cows. This study was done By the University of Florida and they looked at basically colostrum yield and colostrum quality from 11 experience-
From 11 experiments and about 4,200 cows. So they looked at colostrum yield after the first milking and then analyzed that for IgGs, fat, protein, lactose, and lots of other parameters. So they collected lots of information on this, and this was more of a kind of a genetic study as well that looked at trying to estimate some correlations and heritabilities of colostrum yield Basically, it came to colostrum yield was influenced by calving season, so spring, summer, winter, or fall.
Parity, so basically first lactation cows versus older cows. Sex of calf, birth weight, gestation length, and days dry. So what do we see here? So
Cows that calve in the spring and summer tend to have higher colostrum yields than in the fall and the wintertime. Of course, we have seen that in numerous studies, and now we see it even in the South. So more colostrum yield in the spring and the summer
The older cows tended to have more colostrum yield compared to younger cows And cows that had twins had more colostrum yield. Cows that had male calves also had more colostrum yield compared to cows that had female calves. So it's interesting that cows that are having bull calves tend to have more colostrum yield, quite possibly 'cause maybe they're more...
The thought is maybe they'll eat more. They're a little bit larger calves, so the cow produces more colostrum compared to if they're having a heifer calf
calf body weight. So basically cows that had larger calves tended to have more colostrum yield
Cows that had longer gestation lengths had more colostrum yield, and again, cows that were dry longer had more colostrum yield compared to cows that were not dry very long So if you look at IgG levels, so colostrum quality, that was influenced by calving season, parity, and days dry. IgG levels tended to be higher in the fall and winter compared to the spring and summer.
So higher IgG even though the colostrum yield was less for fall and winter-born calves Cows, uh, cows that had greater lactation number had higher colostrum quality, and we know that. And then cows that were dry longer had lower quality colostrum, so they may have had more colostrum yield, but they had lower quality colostrum
If you look at some genetic heritabilities, so colostrum yield .30, IgG .28, total IgGs .25. So it basically shows that there is some genetic component to colostrum yield and colostrum quality. So there is some influence there With the genetics of, of the dam
So basically, in the end, the conclusions were that colostrum yield and colostrum quality were associated both with phenotypic and genetic factors and basically with the moderate heritabilities that you see around .3, this suggests that we could make some improvement by genetic selection in colostrum yield So with that, there's a few studies, kind of some interesting ones that I saw at the dairy science meetings in Milwaukee last week, and maybe we'll talk about a few more that I saw related to heat stress.
I know heat stress is becoming quite important. There were some on cows, some on calves, so maybe we'll talk about heat stress next week as we move into some hot times here, at least in the Midwest, where we're probably gonna look at 105 to 110 degree heat indexes for most of this week. So hopefully everybody stays cool, the cows stay cool, calves stay cool, everybody, uh, does okay.
So with that, I think we'll leave it for today, and if you have any comments, questions, scathing rebuttals, feel free to contact me at The Moo's Room. That's T-H-E M-O-O-S R-O-O-M @umn.edu, or you can find us on the web at University of Minnesota Livestock Extension, or UMN WCROC Dairy. And with that, I hope you have a great week.
Bye.