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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 Moo's Room. I'm just back from the county fair finally. It was a long week at our fair here in Minnesota, our county fair. My kids were showing dairy cattle there. We showed all cows, so we had a Brown Swiss, Guernsey, a Jersey, and two Holsteins. My daughter was grand champion with a three-year-old registered Holstein sired by Delta Lambda.
I was quite impressed. My other son had a very good 85 Luster P daughter that was honorable mention, and we did pretty good with the other ones. The Guernsey, uh, did quite well, although she's maybe got a little bit of a foot issue that I'm gonna maybe correct tomorrow. The vet told me we maybe could be developing a abscess in her foot.
She was kinda limping the last few days, so we'll see. But alas, I'm back. I'm tired. Uh, for those of you that go to county fairs and have cattle, it is a long week for us. It was five days, morning and night, milking twice a day. And we have a very nice display, uh, here at our county fair as well. We have actually a freestall barn inside of our dairy barn.
It's very modern, new barn built less than 10 years ago. It has eight freestalls, a rapid exit parlor. It's just, it, it is the best dairy facility you will find at a county fair. I, I haven't found another one. So if you're ever out in Western Minnesota, feel free to come by Morris, Minnesota and check out our county fair.
It's wonderful. We've got quite a few cows and lots of livestock. Anyways, Sunday evening, back from the county fair, trying to record a little podcast and I wanna just talk briefly about a study here. It came from one of my colleagues. It was actually his PhD thesis, Isaac Sulfer, your dairy nutritionist, uh, University of Minnesota, and we've done some rhythm, annual, annual rhythms of milk with our dairy herd here in Morris.
And he just had a, some of his last work from his PhD come out on herd management factors that are associated with milk synthesis, feed intake, and feed efficiency in Western United States dairies.
So we're gonna
So really we're gonna talk about the biological clock of a cow again and try to figure out what might be contributing to some of these different production and management factors that we see. But basically, we know that dairy cows possess a 12-month biological clock And these repeating cycles really evolved to help predict seasonal environmental changes and maximum survival.
They're really day to day and occur with changes in natural photoperiod that really works like human management. And we know photoperiod especially in, in people ourselves, and we have photoperiod and there's melatonin that's released that works through some of the glands in a cow, and it really makes these phy- changes that we see from milk yield or intake So what the, the study was from a database from Diamond V, which is a company here based out of Iowa, and there were 332 herds collected over a little more than a 10-year time period from 2006 to 2019, and they looked at herds in the Pacific Northwest, in California, the Southwest, so Arizona, New Mexico, and Texas, and the Upper Midwest, so Minnesota, Iowa, Wisconsin, Michigan, and the Dakotas And they tracked milk yield components, so fat and protein, dry matter intake, and feed conversion efficiency in all of these dairy records that they had.
So kind of the baseline, if you think about it On a dairy cow
They kind of have a universal rhythm where every region, breed, and housing system kind of follows a fundamental biological timeline. So milk inherently Kind of goes down a little bit in October Dry matter intake peaks early to mid-February. Yield milk production peaks kind of mid-April, and fat and protein components kind of peak early to mid-January.
So we see this time and time again in all of the studies that kind of have, have happened
So this study basically looked at how human intervention, so management, that alter natural sunlight exposure or they force nutrient partitioning really should maybe think about disrupting the natural rhythm of a cow. And we're gonna see how some of these factors play into it because the rhythms of a cow are highly responsive to biology, geography, but we really don't know much about how management affects that.
So we're gonna look at geographic region, breed, so Holsteins, Jerseys, and crossbreds, housing type. One, they had some organic dairy herds in here, and then they had herds that were flagged by BST usage. And I know BST is maybe not as important anymore as what there used to be, but anyways, these herds certainly were coded as some BST, and we can see what, what that meant from a management perspective
So if we look at geographic region, so milk yield kind of followed a 12-month annual rhythm in all of the regions. So the amplitudes were much higher in the southern regions than what they were compared to the northern regions or the upper Midwest or the Southwest, which means that they had stronger peaks in kind of those southern regions, more peaks and more valleys, whereas kind of flat across time for upper Midwest and the Pacific Northwest.
Milk components, so fat and protein peaked in January. The Pacific Northwest had higher amplitudes for fat compared to the upper Midwest If you think about milk production, so the rhythm kind of hit the harder in the south. So the Southwest and California, like I said, had greater amplitude than the upper Midwest or Pacific Northwest.
And dry matter intake, so all regions kind of showed a peak between February 1st and February 20th, and the Southwest had the greatest amplitude, so a lot of different peaks and valleys
We think about milk yield peak in California happens about April 7th, in the upper Midwest, March 2nd, Pacific Northwest, maybe a little bit different, March 26th. Fat kind of all around January from January 9th to January 22nd, that's when kind of fat production peaks. Dry matter intake, kind of the amplitude was variable much greater in the Southwest compared to the other regions.
Well, what is the influence of breed? If you think about Holstein, Holstein had the highest amplitude for milk production. That means the highest peaks and valleys. It had the highest absolute fat yield, and peak milk production occurred on April 11th. So it's kind of interesting that we can kinda pick out when peak yields are happening just based on the amplitudes and the rhythms of a cow Jerseys, which is kind of the component breed here, obviously they had the highest amplitude for milk and protein concentration much greater than the other breeds, which we'd expect Jerseys to be a, a fat and protein breed compared to some of the other breeds
The crossbreds had a greater amplitude in feed conversion efficiency than Holsteins. So a much greater swing in feed conversion efficiency in a crossbred cow compared to a Holstein. And this really indicates some extreme seasonal variation in nutrient partitioning for these animals
So really genetics kind of scale their response and low
So what about housing sys- systems? They have freestalls versus loose housing. So the expectation was, was that loose housing kind of exposes cows to natural photo periods, so their biological rhythms should be much more extreme. But really there was no difference between free stall or loose housing, so no statistical difference.
Amplitudes for fat, protein, milk yield were identical regardless of the housing type. Feed conversion efficiency kind of flipped completely, where free stalls peak in efficiency in June and loose housing peaks in November. So kind of interesting there how some of the freestall and loose housing actually change a little bit What about management in organic or conventional herds?
So organic herds showed slightly higher amplitudes in milk f-fat and protein. However, the milk yield peaks were the same as conventional herds. Obviously, the organic herds are gonna peak at lower yields, but they peaked about the same time in milk production, which was kind of about February
A BST usage, so kind of BST, the expectation is that it forces energy redirection to the mammary gland, which should flatten out natural seasonal dips in production. The reality was yield and components persist completely intact. So really, the hormone doesn't stop the biological clock of a cow. It just doubles the amplitude for feed conversion efficiency and kind of delayed the peak efficiency by about three months, so April versus July.
So it maybe affected it a little bit, but not as much as what we might think about it
So this research really provided new insights into nutrition-related metrics, and that suggested that dry matter intake rhythms are driven more by an internal biological clock than really temperature alone outside. So dry matter intake peaked in the late wintertime, so February, which really coincided with peak milk fat and protein yield.
And it really contradicts the expectation that dry matter intake would be the highest in the northern regions during the wintertime to support kind of thermogenesis or trying to keep warm during the wintertime. Instead, amplitudes were higher in the southern regions, which suggested the rhythms is a response to nutrient demands for milk synthesis.
Feed conversion efficiency peaked in late spring and late summer. There were some regional differences where Pacific Northwest and California kinda showed different feed conversion efficiency rhythms compared to the Southwest and the upper Midwest. But that might have differences due to byproduct feeds like almond hulls, citrus pulp that they feed on California and the Pacific Northwest
So the key findings here were annual rhythms of milk synthesis and feed intake are certainly robust, and they persist across diverse management systems, housing types, and the use of BST, which not many herds are doing anymore. There was certainly some regional sensitivity, so there was a swing in the rhythms where the lower latitudes experienced more dramatic shifts in milk yield volume, so the Southwest California compared to the Pacific Northwest and the Upper Midwest
Dry matter intake peaked of February across all of the groups, which really suggests that nutritionists can better predict herd management performance because we know that dry matter intake is gonna peak in kind of that February And then breed variation. Crossbreds may possess higher seasonal variation in nutrient partitioning compared to Holsteins or Jerseys.
So really, we shouldn't really assume that the sudden dip in October milk yield is a nutritional failure or management crisis. We should really think that, you know, month over month yield expectations are really gonna be flat So really what are some big components that, that we can do? So we should benchmark herd performance against our cow's biological clock.
We should evaluate the seasons and maybe not just the previous month like we tend to do a lot. So what are kind of actions for nutritionists? Well, we should pre-plan our diet formulations. We know that peak intake is gonna be in February, and peak efficiency is gonna be in June and July, and that really runs on a biological clock of the cow, and we know that.
So kind of interesting, a few things that happens, you know. The, the biological clock of these animals is always gonna be there. It's been there for a long time, and it's always gonna be there, and there are some differences in geographic regions and breeds, and really our management housing situation can't really stop it.
So we need to work with these rhythms of our cows, the biological cows, and not work against it. So with that, I hope you learned a little bit about the biological clocks of a cow and what might happen on your dairy and some things that you, you might see into the future. So with that, I think we'll leave you there today.
I'm gonna go to bed. It's, uh, been a long week. So 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 contact us on the web at University of Minnesota Livestock Extension or UMN WC ROC Dairy. Hope you have a good week. Bye.