Kirby begins with a description of the mechanism of amylase-enhanced corn. The amylase is located in the kernel and, once activated by temperature change, works to increase the digestibility of the starch. A small amount of activation is thought to occur during silage fermentation, with further activation once it reaches the rumen. This paper evaluated digestibility and milk production in cows fed corn silage made from a hybrid with the amylase-enhanced gene compared to the same hybrid without the genomic enhancement. (4:51)
Kirby begins with a description of the mechanism of amylase-enhanced corn. The amylase is located in the kernel and, once activated by temperature change, works to increase the digestibility of the starch. A small amount of activation is thought to occur during silage fermentation, with further activation once it reaches the rumen. This paper evaluated digestibility and milk production in cows fed corn silage made from a hybrid with the amylase-enhanced gene compared to the same hybrid without the genomic enhancement. (4:51)
The experiment was designed as a factorial with four treatments combining the two different types of silage with either 25% or 30% starch in the total diet. Only the silage was amylase-enhanced, not the corn grain that was fed. Kirby expected the amylase-enhanced silage group at 25% starch to perform best because he expected some subclinical rumen acidosis and potentially some feed intake issues at the higher dietary starch concentration. (9:09)
The experiment was eight weeks long, consisting of a two-week covariate and then a six-week feeding period with 11 cows on each of the four treatments. Blood and milk samples were collected weekly. Total tract digestibility was evaluated twice over those six weeks, once soon after silage harvest (approximately 40 days) and again six weeks later to evaluate whether the impact or efficacy of the enhanced starch enzyme changed over time. (13:29)
One surprising result was that the two silages had different in vitro NDF digestibility during week one of the feeding period. The amylase-enhanced silage had higher fiber digestibility even though the genomic enhancement is for starch digestibility. Kirby is unsure of the mechanism but hypothesizes that the amylolytic enzyme may free up some simple sugars or polysaccharides that allow microbes to have greater action and more energy available to digest fiber. By week six, the in vitro NDF digestibility of the two silages was essentially the same (15:09)
Kirby mentions that if he could do this experiment again, he would do a longer-term study for 12 or 18 weeks and start feeding the silage as green chop right away to evaluate if ensiling takes away some of the benefits of the amylase-enhancement. (19:02)
From the production data, the alpha-amylase enhancement didn't provide a benefit, but a fairly consistent benefit of additional dietary starch was observed, including increased feed efficiency, increased energy-corrected milk, and increased milk protein yield with few to no interactions in these results.
Kirby also would like to have some data looking at the impacts of these types of diets on fresh cows since the cows in this experiment averaged 160 days in milk at the start of the feeding period. (24:11)
The alpha-amylase-enhanced silage did not impact body weight, body condition, or feed intake. Kirby anticipated that the higher starch-fed cows would experience greater body weight gain in the later lactation period, but he observed the opposite. At the end of the study, an interaction was observed for feed intake where the high starch cows ate a little less - around three pounds. This resulted in a difference in feed efficiency for the high starch cows, where their intake decreased, but they maintained milk production. (25:29)
Bill asks if the feed efficiency data was adjusted for the difference in body weight change, but Kirby responds that it was just gross feed efficiency, milk over feed. Bill wonders if that adjustment would make the two groups’ feed efficiencies closer together, where it’s more of a difference in how nutrients are being partitioned rather than a difference in feed efficiency (27:26)
Another follow-up experiment Kirby would like to conduct is another factorial with the enhanced silage variety and the non-enhanced combined with a higher and lower rumen degradable protein concentration. (35:16)
Bill wonders if this experiment was conducted with silage at a later maturity, say 40-42% dry matter, would the amylase have a bigger effect? Kirby thinks there is a chance that as the kernel dries down, the amylase may have a greater impact. (38:53)
Kirby’s take-home messages for the audience are to consider the amylase-enhanced gene as an approach to bridging an inventory challenge gap from year to year and not to avoid dietary starch due to worries about subclinical inflammation.
Kirby’s paper can be found here: https://www.journalofdairyscience.org/article/S0022-0302(23)00309-0/fulltext
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Scott (00:07):
Good evening everyone, and welcome to the Real Science Exchange, the pubcast we're leading scientists and industry professionals meet over a few drinks to discuss the latest ideas and trends in animal nutrition. Hi, I'm Scott Sorrell. I'll be your host tonight here at The Real Science Exchange. And tonight we cuss and discuss many things during my favorite segment. And that's the Fable Journal Club with Dr. Bill Weiss. So, welcome Bill. Thanks for joining us again tonight.
Bill (00:33):
It's good. Good to be back, Scott. Thanks.
Scott (00:35):
So, before we dive into tonight's paper, let's start by introducing our guest bill, if you wouldn't mind going ahead with that. Well, first, first question, what's in your glass tonight?
Bill (00:47):
Well, in recognition of the Buckeyes beating Notre Dame a few weeks ago, I have a, a, something green, Irish Irish logger.
Scott (00:57):
Alright. Outstanding. Outstanding. Would you mind going ahead and introduce your future Buckeye guest tonight, bill?
Bill (01:06):
Okay. My pleasure to introduce Kirby Krogstad. I'm not Norwegian, I can't pronounce it exactly right. He's completed his PhD at Michigan State. He got his master's at university of Nebraska, and I'm happy to say he will be becoming a Buckeye at the first of the year up at Worcester, up at OARDC, kind of taking my old position.
Scott (01:32):
Yeah, good deal. Good deal. So, welcome Kirby. Kirby. I'm gonna ask you the same question. What's in your glass tonight?
Kirby (01:39):
I'm a whiskey guy, so it's usually, usually a whiskey
Bill (01:42):
Of some sort.
Kirby (01:43):
Woodford, when I'm not on a tight budget.
Scott (01:48):
Okay. Very well. All right. And finally, happy to welcome back my good friend and co-host, Dr. Clay Zimmerman. Clay, what's in your glass tonight
Kirby (02:00):
In honor of the season? I have some apple cider in my glass tonight.
Scott (02:05):
We've got a new pub in town. It's called back Road Brewing Brand New, and they've got a pickle flavored cider that I absolutely love. Yeah, it's, and yeah, you either love it or you don't is what they tell me, but I happen to be on the I love it side of it. So anyway, I've been having some cider and I think of you of course, as always, but what's in my glass tonight? Well Kirby mentioned Woodford's Reserve. That's what I have tonight, and I'm having that in honor of a new friend of mine Mark Scott from Fi Animal Health. Mark and I attended the IFCN Conference last week in Chester, England. And we met up in the pub afterwards and Mark's a fan of the podcast. And so we enjoyed both enjoyed Woodford's Reserve. So here's to Mark Scott and new friends. Cheers.
Kirby (03:04):
Cheers.
Scott (03:04):
Cheers.
Speaker 5 (03:05)
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Scott:
to begin our conversation tonight. Bill, I'd like for you to share why, why did you select this paper and what, what is the hypothesis?
Bill (03:36):
Well, the paper is, I'm gonna abbreviate the title. It's a little long, but it's the effect of amylase enhanced corn silage with different dietary starch concentrations on milk production, digestibility, and some blood and metabolites. And it's in the journal dairy science earlier this year. I didn't write the month down, but earlier this year in 2023 I picked this one, this was when I was still an extension. This silage was just coming on, on the market for dairy cattle. And so we were getting lots of questions on it. So I've kind of followed up on it. We did a little bit of research right at, when I was leaving Ohio State. So I have an interest of it, and it is of, of practical importance to, to dairy producers. 'cause You know, selecting hybrids for silage is a major decision they have to make every year.
Scott (04:27):
So, you know, as we kind of jump into this bill, I'm wondering if you wouldn't mind kind of explaining how Emily's enhanced corn silage actually works and, and what it's intended to do.
Bill (04:40):
I should let Kirby take that. He's the expert. So I'm gonna, and if, if you give us a little background on the gene, how it's in there and, and what it was originally for and what it's being used for now.
Kirby (04:51):
Yeah, yeah. So like, like Bill was saying earlier, this is a cool project to do 'cause it has such practical application. And I didn't realize how relevant this gene was till I got out to Michigan. It's being used on more and more acres every year. But all the amylase itself is, is a, a gene enhancement in the kernel of the corn. It was originally designed for ethanol production. Actually. They were trying to increase I think ethanol efficiency yield from every bushel of corn, you know, to continue increasing the efficiency of ethanol production. And I think the story they tell is they had a farmer who grows corn and has a feedlot and he had some of this leftover experimental corn that had the amylase in it. And so, or the enhanced amylase gene, he said, well, I'm gonna feed this to my cattle.
Kirby (05:35):
And he had two pens side by side. And every time he walked him, he just thought that one pen looked really good and their gains were a little bit higher than the other group. And he brought out, brought out the company folks and researchers said, what do you think of this? And so then they realized maybe they've got another application for this technology. So it's really, it's just, it's inserted in, in the genome and it's a long, it's in the endosperm alongside the starch is some of the logic. And so basically the idea is once it gets in the room and the amylase is right where it needs to be breaks up, the starch makes it more available and hopefully more digestible for the cow. And so that's kinda what we were looking at is, is when you put your money where your mouth is, does the digestibility and milk show up in some different scenarios?
Bill (06:17):
And the gene is only in the corn kernel. It's not in the plant like, you know, BT corn that's throughout the plant. But this gene or this is expressed only in the kernel.
Scott (06:27):
And so you said in the beef cattle, it it, it, it activates in the rumen, I'm gonna assume that for dairy cattle in the silage, it's gonna activate in the, in the, in the pit. Right.
Kirby (06:40):
If not, this is where I get a little bit fuzzier. I think it's supposed to be activated upon temperature change. So they say like once the silage heats up and ferments, it's supposed to activate a little bit. And then once it hits the body temperature in the room and it's supposed to be more active 'cause it's a high temperature active amylase. The original biochemistry paper about the gene has some more details on that. But I think the temperature change is what they talk about mostly. And I mean, it's, it's interesting 'cause the beef cattle research does show some, some gain to feed benefits when it's dry rolled corn. I believe when it's when this corn is insiled as high moisture corn or corn silage, they don't see it so much. But in dry rolled corn, they actually saw a little bit of a bump in their feed efficiency. So there's some encouraging evidence out there in the beef and dairy so far with this, with this hybrid or with this gene in these hybrids.
Bill (07:31):
Yeah. And you know, unlike BMR, which is, you know, great silage, but you have a significant yield drag with BMR, this one doesn't appear to have any agronomic issue. So the yields are very similar. It's just the gene is the only thing really different on this.
Kirby (07:47):
So that was actually the only thing I hadn't heard so far. Have you been hearing that from the field bill? I'm{p;l/ not familiar with any yield trials or anything like that, but I do get that question.
Bill (07:55):
Yeah, the yield there, there is some yield data from the company and I just was, wherever I was just at, I was hearing some of this again, dairy Expo, they were talking about different hybrids and it doesn't appear to have a yield drive or if it is, if it is, it's very, very small.
Kirby (08:12):
Well, that's good to know.
Scott (08:13):
So Kirby, in this trial, were, were the two hybrids the same other than other than the alpha amylase?
Kirby (08:22):
Yeah, so I, I try to be careful about using the word hybrid 'cause I don't know if that's the proper word in this case, but it was an isoline corn hybrid and the same hybrid just with the amylase gene enhancement. And that's actually, thankfully when you're doing, and I think Bill could speak to this too, when you're doing forage research and you ands two forages, you're kind of just preying, they turn out relatively similar in some cases. And that's what I was most happy with, as these were side by side plots, you know, just one plot of each right next to each other in the field. And after fermentation and the nutrient specs and all that, they actually came out quite similarly. So we felt like we had a nice comparison of is this gene itself helpful to the cow? 'cause The starch and fiber came out relatively close, which we were quite pleased, but
Bill (09:09):
Well, yes. Just to get into the paper, you, you, you're the two, you have four treatments. One is the two, two I'm gonna call 'em hybrids, I don't know if that's the name or not, but the two types of corn silage. And then as a, as a factorial you had a 2020, 5% and 30% diet starch. And whenever I read papers with a factorial, the question that comes up or that should come up to everybody is what, what interaction. That's the only reason to do a factorial. What interaction were you expecting in your, say your hypothesis?
Kirby (09:42):
Yeah, I was, I was expecting for Enogen to, well the alpha ly enhanced, the brand name is Enogen to perform better at the lower starch concentration. 'cause My thought is once you go to the higher starch that you would have some subclinical rum acidosis and possibly some feed intake issues, especially 'cause these are mid lack, mid lack late LAC cows. And so they may not need all that diet for amenability and they might back off on feed intake a little bit. And so that was my initial hypothesis. 'cause I'll tell you what, being in South Dakota, Nebraska we don't feed nearly as much starch as they do out here in Michigan. I was on farms with the nutritionist and I couldn't believe it. I was like, my god, you guys like your corn out here. You know, it's in, in South Dakota, Nebraska, 24, 25, 26 starch, pretty normal. Some guys will push it a little farther when they have really good forage, but man, everybody out here is like 29, 30, 31. And so I was impressed by the amount of starch these cows can handle during my time here in Michigan.
Bill (10:38):
And, then I think one thing we just need to remind listeners of is the gene is only in the silage. It's not in the corn that you fed. So, you know, the, I I didn't calculate it, but only a certain proportion of the DIA starch is actually in, in, in the corn silage. And then the other really interesting thing I think you did here, and that is your, you know, your hypothesis said basically that in fresh corn silage or early corn silage, it may have a bigger effect because, you know, after months and months of sitting in the silo, we think star digestibility increases in vivo even though that's eight is not real clear on that. So that, I think, was really good where you did it. I think it was like 40 days of soiling your first digestion, then you did it mm-hmm. Six or eight weeks later. I think that was really good.
Kirby (11:31):
Yeah. Thank you. That was, that was Dr. Bradford's grandchild and we wanted to do 15 days, but you know how logistics happens sometimes you can't get the cows in time.
Bill (11:40):
And then one other last detail here, you did kernel process both silages with the same chopper. Do you have any metric on how well you process this, you know, kernel processing score or what you set the rollers at or something like that?
Kirby (11:57):
I don't have that on hand. All I have is we were kernel scoring throughout the day, you know, the pioneer cup kernel score and our, one of our teachers and then the nutritionist have benchmarks that they set and we were meeting those throughout the day. So all I can say is they were both, I would say, processed to, to meet our nutritionist expectations.
Bill (12:17):
Okay. I think we can go ahead and, well, one other thing you measure for, I forget, is, is a measure of, of inflammation. You used acute phase proteins and all, you know, there's a bunch of those and you used two of them, was there you used ss a, a serum amyloid and then half the globin. Is there any reason you picked those two out of all the other ones or?
Kirby (12:47):
Mostly, I think right now in the dairy science literature, those are probably the two most prevalently measured. You could probably add LBP lipopolysaccharide binding protein as well. But we have high confidence in these two Eliza's. You know, the hard part about working in bovine is it's hard to find bovine specific Eliza's that you have confidence in. And we have a great deal of confidence in these two assays, and we have so much more data, especially on haptic globin. So that's why we picked those. It was, you know, that there's other things to compare to within the literature and within our own data in the lab.
Bill (13:17):
Okay. Well if you wanna just explain real brief, don't we don't want details on stats or anything like that, but just the basic outline of the experiment any big picture items?
Kirby (13:29):
Yeah, so the experiment was eight weeks long. We had a two week covariate and then a six week feeding period where we had these four diets and we had 11 cows on each of these four treatments. Like you said, test the interaction that we thought would show increasing starch with this hybrid may actually reduce performance. And we saw the opposite. Well, I shouldn't say we saw the opposite. We didn't observe that interaction, but, so that's kinda the big picture of the experimental design. We did weekly blood samples, weekly milk sampling, and as you mentioned, we had a unique aspect of this experiment with two digestibility periods. Traditionally you do a digestibility period after five or six weeks on a diet so they can adapt to it. But we really wanted to do two things. One, look at the digestibility soon after harvest, and then two look at the digestibility again six weeks later with the idea being one that longer and sing would reduce the EFF efficacy or reduce the impact of that enhanced starch enzyme.
Kirby (14:27):
And the second being, there's some data, there's a couple of abstracts from, I think it's 2019 ASDA, where they had some silage fermentation profiles of Enogen or the Alpha AMS enhancement and the non enhanced isoline. And the enhancement actually seemed to promote a more rapid stabilization of the silage. So you know, that initial spike and then come back down and stabilizing seemed to be more rapid and efficient with this alpha amylase enhanced alpha amylase enhancement. So that was part of the hypothesis here too, as these cows might adjust more smoothly, switching to this amylase enhanced silage, which is why we have some of the silage fermentation data. But big picture, that's what the study looked like.
Bill (15:09):
And you used just to power, I think 44 cows. So it's a well powered, well powered study here. On results, there's a couple things that I found surprising. One is the, you know, on the in vitro NDF digestibility at very early on, I don't know if this was week one of insiling or week one of the experiment, I didn't quite understand that there was a huge difference in, in vi what, what do you think? And, you know, this is an amylase enzyme, not a lytic enzyme. What do you think? And this was the in vitro data. Yeah,
Kirby (15:47):
We spent a lot of time chewing on that. And I spent a lot of my time thinking about NDF digestibility, but we're, long story short, we're not entirely sure. But the only thought we have, and this actually came from an amylase enzyme paper, I think you had published back in 2011, 2012, that maybe, you know, we're freeing up some simple sugars or polysaccharides with this enzyme in the corn. And then that's allowing microbes to have greater action and more energy available to them, to actually chew through all this fiber. But I mean, we, we really don't know, but we were surprised, and this is one of those interesting results that actually carried through in vivo. So we had the in vitro NDF that bumped by three points, and then we carried that through and we saw a bump in fiber digestibility in the cow. So it was kind of interesting. We were actually, that's the most exciting result of this paper for us. And we're not sure where that comes from.
Bill (16:48):
And, you know, by six weeks then it, the in vit again in vitro fiber digestible was the same essentially between treatments. Yep. So what, again, what do you think is going on there as the enzyme is dying off? Or is the control just getting better by sitting in acids for six weeks?
Kirby (17:08):
I, personally, think the control, like you said, the control is kind of catching up. I think with, it's like, it's like what fuel's available at the time, and I think maybe there's just more fuel available in that alpha amylase enhanced kernel early on, and then six weeks, eight weeks, 10 weeks later, maybe that control hybrid without that amylase enhancement is caught up and that there's the same fuel left. I wish I had a better, clearer answer, but I'm still chewing on that one. I'm not entirely sure. And I will defend here in three weeks, so I better come up with a better response.
Bill (17:41):
Your advisor might be, listen to this. We have get more questions.
Scott (17:44):
Kirby, I'm, I'm curious in, in the control corn silage is, is there alpha amylase activity in that?
Bill (17:53):
In those kernels or, or
Kirby (17:56):
So, to, to be clear, we don't have that data from this paper, but there is two other publications that have that. And I think both the CUEVA 21 and rebelo, the Ohio State Paper 2022 or 2023, excuse me. I think both of those had some amylase measures, but a control silage has a very low basal level of amylase activity. It's not zero, but it's near zero. Okay. And this enhancement, according to the Penn State data from 2021, increases that activity. I think it's like sevenfold to tenfold. It's a very large dramatic increase. Okay. And that, and the Penn State data was after like 180 days of inci. So, that amylase is very stable and very active for a long time.
Scott (18:45):
Okay. Kirby, I'm kind of curious knowing what you know now. How would you design the protocol, the protocol maybe to take a look at what's happening there in the silage? Would you maybe track microbial populations and species, those kinds of things over time? Just kind of curious.
Kirby (19:02):
Yeah, I think if I could do this again and I'm, I'm hoping to be able to do something like this again, crossing my fingers when, when I get down into Worcester I would like to do a longer term study, 12, 18 weeks, something like that. But then start feeding it right to green chop, you know, green chop, start feeding it right away, comparing these two hybrids. 'cause the idea B may being that if Insiling takes away some of the benefit of this Alpha am lease enhancement, we would see that over 12, 16 or 18 weeks in a set of cows. That would be what I would probably redesign. I think there is some microbial data from Penn State in the dissertation of this student that published this work, and they have some minute differences in the microflora of the rumen, but I don't think they were very substantial that I'd think, you know, that's driving the digestibility difference. So I would think more of the timeline and time timeline relation to harvest would be really interesting.
Scott (19:59):
Yeah, I was even thinking maybe looking at microbial populations within the silage itself Oh, sure. And how that may be changing. Sure. Yeah.
Bill (20:06):
Do you know of any, I know that I read the Penn State paper, but has anybody looked at amylase activity, say from green shop in the silage from green shop out to even 300 days?
Kirby (20:19):
Not that I've seen.
Bill (20:20):
Okay. 'cause I haven't either. And I said the Penn State one says it's still active, but I don't know if it's as active as it was at day zero.
Kirby (20:27):
I don't Right. It's, you can't, you can't assume that level was there at zero or there at 300. Yeah, I agree.
Bill (20:36):
You know, we talked about in vitro fiber, you looked at seven hour starch disappearance.difference on
Kirby (20:43):
And it did the same thing. Big Day. Again,
Bill (20:44):
I'm calling, I think it's week one
Bill (20:46):
And essentially no difference on week six or seven. Again, what that, that's to me is more strange than the fiber one. It's what, what, do you have any idea on why it, why the difference disappears? I guess? Not that it was different, but why did it disappear?
Kirby (21:04):
Well, I think I, for me, logically lines up with some of Pareto's work that as that starch kernel ferments in a silo over the time, over time we get a little more rapid starch digestion. And that maybe once that kernel sits in the silo for 6, 8, 10 weeks we lose some of the advantage of the aase enhancement. I think that lines up fairly nicely. But the other thing to consider, and anyone that's worked with in vitro knows this, is those are variable assays, right. And, and sometimes you could just have an assay to assay variability as well. So there's that to consider. So like with some of these in vitro data, I would like to see them repeated either in more studies or even just do a time series analysis with some more plots. 'cause That's the other thing to remember, these were one plot side by side, so it's not a really well replicated design for the planting of the hybrid. Yeah.
Bill (21:57):
And I was in Dairy Expo just last week given a talk, and I, I've gotten this question, I don't know how many times, but I just got it last week. And that is what, how does a nutritionist or what value is this? Seven hour starch, whatever hour you want, but in vitro starch disappears, what we know, it doesn't predict total track starch, I guess. But that I, I can always answer that one. But, what do you use it for?
Kirby (22:26):
I, I think it's a, it's still a fairly reasonable tool to, to compare things relative to each other. So if you have two silages that, you know, might be the endosperm difference or, or just some innate difference in the, in the starch that makes it more or less digestible, I think it's nice to have the relative comparison. But when it comes to feeding cows in the field that you're right, it doesn't have the utility of we're gonna get X more energy out of this hybrid or X more microbial protein. 'cause The seven hour starch said so. So I think it's still a nice tool for relative comparison, but beyond that, it probably needs polish to really have a really strong field application like that.
Bill (23:10):
Well, we hop into the production results and, can you give us just an overview of the major, major production findings you found?
Kirby (23:19):
Yeah, I think fairly simply is, the alpha amylase enhancement didn't provide benefit in this, in this case, but we saw a pretty consistent benefit of the additional dietary starch, increasing feed efficiency, increasing milk protein yield with limited to no interactions on those results. So that would be the bottom line take home for this paper is the amylase didn't provide a benefit, but the higher starch diets certainly did. And, the starch was higher efficiency and I can't remember. And high, well, higher milk energy corrected milk and higher feed efficiency, basically. Yep and mostly driven by milk protein particularly, we got more milk protein out of those higher starched cows.
Scott (24:06):
So Kirby, what was, what was the stage of lactation of cows in the study? Yeah,
Kirby (24:11):
That's a great question because that's kind of one of the things I like to think about in context. So these cows started at about 160 days in milk. And so then you've gotta realize they started at 160 days, but it was a 42 day study, or a 42 day feeding period, you know, six weeks. So by the end of it, they were 200, 200 and 210 days. So they were tailing off production as we came to a close. So I was actually, I'm glad you asked that. 'Cause That's what I've mentioned is I think that's a gap that there is in this data is we don't have. I think we have two of them, there's three published studies. I just had an article in hoards that kinda reviews the data for this amylase enhanced silage. And I think two of them come in mid lactation cows that a hundred thirty, a hundred forty, a hundred fifty days. And one of 'em has cows that started at like 80 or 90 days in milk. What we don't have is that fresh cow. And that really early lactation cow. So I think that's a gap here and something to be considered about. 'cause It's easier to drive up peak milk in those early cows and change than changing milk in a post peak late lac cow. It's pretty tough to move those cows off their trajectory.
Scott (25:18):
Kirby, did you measure body weight and body condition score? And if so, did you see any differences there with the amylase and, and, and higher starch diets?
Kirby (25:29):
Yeah, we did. We did measure body weight and body condition weekly. And we actually, we had a head scratcher on the body weight result. Again, we didn't see results of the alpha amylase enhanced silage. What we saw was a bit of a head scratcher on body weight. We anticipated that these higher starch cows, these higher starch fed cows, would experience greater body weight gain in the later lactation period. And we weren't prepared for what we saw, which was the opposite. The low starch cows actually gained a bit more body weight than the high starch cows. But when we put that alongside the differences in energy corrected milk, it makes a bit more sense. Those high starch cows continued making a bit more milk later in lactation, and the low starched cows made a little less. So maybe that's where that body weight changed difference comes through. But we were not expecting that. So the high starch cows, more milk led to more milk, less body weight gain, the low starch cows had more body weight gain, but a little less milk.
Scott (26:23):
So was it, Kirby was, what'd you see as far as dry matter intake as you progressed through the study?
Kirby (26:30):
Yeah. So the big picture was again, the amylase enhanced silage didn't have an effect on the feed intake, but we did see that through the study. There was an interaction. We had our week one versus week six feed intake, the week one of the study period, the experimental period versus the final week. And those high starch cows tail off in intake as lactation progresses, which I, I fairly confident aligns with, with data as cows get later in lactation, they start to tail off intake based on energy a little bit. So I think that aligns nicely with how we understand the biology working. But again, it wasn't an enormous difference. It was three pounds. So it's not like it was a 10 pound difference in intake by the end, but a substantial enough, which is where the difference in feed efficiency really stems from, is those higher starch cows tailed off an intake, but they maintained the 40 kilos of energy corrected milk.
Bill (27:26):
Did, did, excuse me. Did you, on the feed efficiency, did you adjust for the difference in body weight change? In other words, give
Kirby (27:36):
The feed efficiency is just gross feed efficiency milk over feed.
Bill (27:40):
Okay. Because you know that with when they change and when there's a difference in body weight change, you know, that's energy. And I did some hand calculations and that cuts, you know, your, the, the difference in body weight is almost a kilo of milk energy and a kilo of milk. So that pulls them, the feed efficiencies pretty, pretty close together. So
Kirby (28:00):
Right.
Bill (28:01):
You want, they're, they may not be any more efficient. They may just be partitioning the energy differently and not, there's no more energy in the diet. It's just where it goes. So. Right.
Kirby (28:11):
Well, I was actually curious to get your guys' input. Is, does that result surprise you with the difference in the starch and the body weight gain? For me, that was a surprise. I expected it to be opposite. Yeah.
Bill (28:21):
That's the expectation. But this is why we do experiments. I did on the, if we get to digestibility, you know, starch hammered fiber digestion as you'd expect but you didn't see, and dry matter digestibility didn't change, or essentially the starch did not affect dry matter digestibility. And dry matter digestibility is essentially digestible energy. They're virtually the same. So I think this is a good thing to remember. You know, starch is supposed to have all this energy compared to fiber, but very often it doesn't really do a thing. And your data showed that very clearly.
Kirby (29:08):
Yeah. I go back to, so I spent my master's degree with Dr. Conan often, and he would always, he was good about making a step back and look at the whole picture like that. And it's like, you know, a gram of digested fiber and a gram of digested starch are fairly similar in their energy concentrations. And it's just a matter of how much each gets, each gets digested. And I love that the new NASEM model came out and, and had that interaction in their digestible or include starch in some of those energy measures or as an interaction. So I was glad to see this data fit that quite nicely.
Bill (29:42):
And then if we look at, you know, the effect silage effect on digestibility, you got a nice improvement in fiber digestibility, very, very significant and biologically important.
Bill (29:56):
But you didn't see any difference in feed efficiency, which again, you'd expect based on the first law thermodynamics, you sit there and say, where did that extra energy go to? And where, where do you, what do you think's going on here? Because you'd expect, I would've expected better feed efficiency with, with your digestibility data. That is
Kirby (30:16):
One of the most infuriating results I've had in my young research career. 'cause They don't align whatsoever. So we either violated the laws of thermodynamics or just haven't put all the pieces together yet. And, you know, I I, I really don't know. I wish I had a better answer than that. I'm, I'm not sure. 'cause With a, and like you said, it was not a small increase in digestibility. It was six seven points. Six seven units. And that's, that's pretty large. You would expect to see an increase in milk yield or, or body weight gain or milk fat or something. And we just didn't observe it here. So I'm, I'm not entirely sure, but also I think it's worth mentioning our data is the most dramatic difference in digestibility across the three studies. There is some encouraging evidence that this gene does provide a little boost to digestibility, but ours is the most dramatic. So I think it's important to recognize that just like in a single experiment, experiments themselves kind of occur on that bell curve. Right. So this may be an outlier of a result, we don't know. So I hope that there's more data coming with this gene feeding it to cows to see if this digestibility result is the median of those results. Or if it is the 1% extreme we, we really don't know yet. But I wish I had a better answer for you.
Bill (31:33):
Do you, do you think, you know, this is again, essentially digestible energy, you'd expect more methane loss with, with the antigen because of more digestible fiber. So do you think if, if you would've measured me or maybe even any, that that would explain it, that the digestible de is higher, but then you lose all these efficiencies and at the end of the day, the net energy the same?
Kirby (31:58):
I think that, I think that would explain a fraction of it. If, if this was a two three point difference in N D F digestibility, I think I would basically say the methane loss and then the energy cascade would probably explain most of it. But it's such a big difference. I think there's something we're missing. Or just some random sampling variants from day to day that may have occurred. I, I'm not, I'm not certain.
Bill (32:24):
And then, you know, you found an increase in protein digestion. Which again, is, is not expected from me anyway. What do you think, is there any, I guess is there any possibility that this gene insertion is changing like ZN concentrations or changing the, the other proteins in this corn? Is there any, I don't know if they've looked at this or,
Kirby (32:49):
Yeah, I'm, I haven't seen anything like that. I haven't seen anything that would suggest dramatic changes in the composition of the corn in general. And I haven't come up with an excellent answer for that. I mean, I, I thought maybe we're getting some kind of ruminal effect that, you know, more thorough protein and nitrogen utilization that's going into milk. And, and, and that's actually suggested across studies. You know, we have the reduction in MUN, the improvement in crude protein digestibility. And a couple of the other studies observed civil of, excuse me, observed similar results. So I think there may be something to the enhancement of the amylase that may be driving some nitrogen use efficiency that I think deserves more attention. The data bears that out so far. I think there's improvement in nitrogen use with these cows. And I think that's ruminal, you know, getting more microbial protein and more digestible protein that way is, is my, my guess. Okay.
Bill (33:55):
So I guess, you know, the, the, you know, if anybody knew anything, you hear amela, you think everything has to be starch. Related to starch and, you know, basically what you found, it was related to everything other, other than starch. So it's important to think, think broader here than just one, one nutrient. All this stuff is connected. So,
Kirby (34:15):
Yeah. Well I think it, I'm, I, I can't remember what it, Cumberland Valley or Dairyland, one of the labs did some correlation analysis where they just took ground corn, put it in water, and measured what was left in the water. And they found an association between what they called soluble starch, which I don't think that's a good word for it, but, and, and the fatty acids that were released. So like you put a bag of corn and water, take it out, the amount of starch and the amount of fat left in the water was correlated. And so we don't have fatty acids here, but that would be an interest, interesting piece of this too. 'cause When you're feeding these high grain diets, you're delivering a great deal of fatty acids from corn. And that's something we don't have here because it's so expensive to measure fatty acids. But it might be an interesting piece of the puzzle as well,
Scott (34:59):
Kirby, I'm wondering if there's an opportunity to fine tune our nitrogen supply making sure that there's plenty of nitrogen available by either supplementing with urea, slow release urea, rheumatoid degradable proteins, that kind of thing. Any thoughts around that?
Kirby (35:16):
Yeah, I think I've been dreaming up all kinds of follow-ups for this. And that's one that I would find interesting is another interaction type experiment where we have the enhanced silage variety and the non enhanced and then a higher and lower room degradable protein. I think there's an opportunity based on the data with reduced MUS and improved milk protein and improved nitrogen efficiency that I've seen across these three studies, that maybe the amylase enhancement would improve the use of R D P and make higher r d p diets more beneficial. 'cause You might get a little more microbial protein and maybe get more nitrogen incorporation into the milk. Again, I think that benefit's probably greatest early after harvest when this amylase seems to be most beneficial. But I think it's worth investigating. 'cause These applied nutrition questions we're kind of tweaking around the edges, right? We're trying to just tighten things up. 'cause We're already really good at feeding cows. We're trying to just really tighten it up, get even better. So I think that's one opportunity.
Bill (36:12):
One other question was a little bit, your data was a little, I won't say confusing, but unexpected is, you know, you have the, the starch really hammered fiber digestion, which is expected, but u usually when it does that, you start seeing some milk fat depression.
Bill (36:29):
You didn't see any of that and any milk fat depression. What do you, what do you think, why do, why do you think the disconnect between them two
Kirby (36:37):
Fir? The first thing I would say is, I mean, our, our milk if we didn't experience milk fat depression on the higher starch diets. But these cows were lower in milk fat than our dairy's at right now. I mean, they were 3, 6, 3, 7 our dairies regularly. The Michigan University research D is usually around four, like three nine to four one. So these were lower milk fat cows in general from what we normally have. But I think when I think about the milk fat depression story and starch, even though we had this dramatic reduction in fiber digestibility, the source of the starch matters, you know, so this was dry ground corn. It was a really fine dry ground corn. But it wasn't a high moisture corn. It wasn't a barley or a wheat that would have all the really dramatic ruminal effects.
Kirby (37:21):
So although N D F digestibility was suppressed, which even, and I I was gonna mention, the reduction we saw is two x what you would expect with the nassa model predictions. We saw twice the reduction you would expect in our fiber digestibility based on that model. So this is, it is large, it is substantial. But I think the source of the starch is why it's, it, it's not it's not a super duper hot dry ground corn. It's not high moisture, it's not some other wet processed corn that would cause some dramatic ruminal changes.
Bill (37:51):
Our digestible are really good. There's, you know, as high as you're ever gonna get. So yeah.
Kirby (37:55):
Even
Bill (37:55):
If it wasn't the super duper starch, it still was, you know, a lot of that could have been in the small intestine. You don't know what was digest, but it was very digestible starch
Kirby (38:05):
Yeah.
Bill (38:05):
For both all diets. So, so Kirby, when, when you ran this study, when did it take place? Like, was it like November to January?
Kirby (38:15):
It was right around there. It was actually I think we started late September ended right before Thanksgiving. Okay.
Bill (38:21):
It was,
Kirby (38:21):
It was the fall part of the year.
Bill (38:24):
Yes. Guess one, one thing I forgot to ask, but I should have asked at the very beginning, what, what, how mature was this corn silage when you harvested it? Or the dry matter con dry matter concentration
Kirby (38:35):
Mean the dry matter came out right, right around the 35.
Bill (38:38):
Okay. So just normal, normal maturity then.
Kirby (38:41):
Yeah. I wanna make sure, let me check the data table. But they were similar. It was, yeah, 35 for both and actually yeah, 35.235 points 0.8. So
Bill (38:53):
If you would've done this, say with 40-42% dry matter silage stuff that was, you know, got away
Bill (39:00):
Do you think this amylase would have a bigger effect than say on mature corn silage?
Kirby (39:07):
I think there's a chance for that. I think as that starch kernel ma or the starch and the kernel matures, the kernel dries down. I think there's an opportunity that this place would have a greater impact. I think that is something worth considering, worth investigating. 'cause We also got lucky, it was a great harvest year when we put this up. I was worried in June, we didn't get any rain. And then we had a wonderful rest of summer and it turned out to be perfect. Put up this silage this year. Maybe a different story. I don't know.
Bill (39:37):
Do you know they, do they have different hybrids with this, with this gene? Or is it just one, one again, I think they call 'em hybrids, but is it just one or do you, can you get some different traits with this or different
Kirby (39:54):
To my knowledge, I think you can get this trait put. I think you can get this trait put into different hybrids.
Bill (40:02):
Okay.
Kirby (40:03):
The thing I still am unaware of and this comes with being a student sequestered in academia, is, I don't know the cost difference of if you have an, and if this AMLO enhancement, the brand name is Enogen, if they have this enhancement, I don't know what the cost difference is for hybrids. And so what I've, and what I've told people is it's not gonna, there's not a reason not to do it. The data's fairly encouraging, especially on the m u n and milk protein piece, but you've gotta cost that out if, if there's a cost difference in the seed, you've gotta decide if that's worth it for you. But I have started to discuss this in the context of if you're a farm that struggles with inventory, if you, if you are always tight on corn silage, come the end of the year, this gene and it's hybrids with this gene, and it might be a really good option for you to get a little bit more out of that transition period when you're switching piles. I think that's where the opportunity lies with something like this, which is why I'd like to do a green chop study and really bear that out. See if there's a huge difference there in, in a green shop scenario.
Bill (41:06):
It would, if that's a, if that works, you know, that would cut down on the needed inventory for any farm. You didn't need to carry three, three months of silage over. So it would've, even if you're not short, it would still be an economic savings if, if that pans out.
Kirby (41:20):
Yeah. And, and it just a cool applied question, right. Really creative applied approach to science that I think is always important to have.
Bill (41:29):
Well, I'm gonna, I'm about done here, but I ask this question to every guest and that is, you know, no, no. Experiment is perfect.
Kirby (41:36):
Yep.
Bill (41:36):
What, what would you do if you could with what you know now, but repeat the same experiment, what would you do? Same treatments, what would you do differently?
Kirby (41:49):
I think I, I've chewed on this a bit and first of all, if we could have started the cows on study when we wanted to and had a, a seven day or two week fermented silage instead of a one month fermented silage, I really would've liked to see what that data looks like. I think a great deal of the story with this amylase enhancement is early in that silage fermentation window. Even though that's only one or two months out of the year, I think that's super valuable. You know, I grew up on a dairy in South Dakota and there were years where when we switched corn silage, we'd lose eight or 10 pounds of milk and we could never figure out why. And so I, I wish we could have started on time, but you know, here, my, my story of doing research at Michigan State is everybody wants transition cows and everyone wants high milk cows. And my PhD has been trying to use everything else. So we kind, we kind of took what we had.
Bill (42:38):
Okay.
Scott (42:39):
They still averaged a hundred pounds of milk at the start of the trial though. Oh
Kirby (42:43):
Yeah. They did. But I think the, I'm trying, I, I try to be aggressive in moving my benchmarks, right? Yes. A hundred pound cow's a good cow. Yeah. It's a really good cow. These cows made a lot of milk, but we have a lot of cows making 50, 60, 70 kilos of milk. And I would love to get some of those on study. Right. And when I go, so my family milks cows in Minnesota over by Rochester and you know, it's a hundred pound herd, but they have pens of cows making 140 pounds.
Kirby (43:10):
So we need more of those types of data sets where we can say these 140 pound cows, what the heck are they doing? And how the heck do we need to feed 'em to be even more efficient? 'cause That's where we're gonna get some really cool gains.
Scott (43:21):
So Kirby was, was the original design essentially the day this was harvested? The cows would've started on the two week covariate?
Kirby (43:31):
Yeah, basically the day of harvest, we're gonna move them in, start the baseline diet with last year's silage. 'cause We wanted to simulate that silage switch and we still did. It's just we didn't do it as soon as we wanted to.
Bill (43:42):
Right, right.
Scott (43:45):
Kirby, do you happen to know if these silages are available in countries outside the us?
Kirby (43:55):
I'm not sure. But it, I mean, it is a AGMO variety. Right, right. Because it's, it's genetically modified. So I know that there would be restrictions and I, I don't know what the country to country restrictions are.
Scott (44:06):
All right. Fair enough. But what I'd like to do is ask you guys just to kind of give us a few takeaway thoughts from today's conversation and are there any, any items or advice that you would have for a consulting nutritionist and based on this research and clay, I'm gonna start with you. Do you have any thoughts for us?
Speaker 5 (44:26):
Tonight's last call question is brought to you by NitroShure Precision Release Nitrogen. NitroShure delivers a complete TMR for the room microbiome, helping you feed the microbes that feed your cows. To learn more about maximizing microbial protein output while reducing your carbon footprint, visit balchem.com/nitroshure.
Kirby (44:49):
Well, first thing, Kirby, I want to congratulate you on your, on your new position there. So
Kirby (44:54):
Thank you. I appreciate it. Congratulations. So I mean, I love this paper really, you know, good, good applied research. It is unfortunate, unfortunate the design didn't work out exactly the way you had intended, you know, to feed it earlier. 'cause I'd be really interested to see how that would've worked in that case. But you know, there's some interesting findings here and a lot of good data really, you know, comparing the lower and higher starch diets here as well that that can certainly can certainly be applied to the field.
Scott (45:33):
Kirby, any, any final thoughts for the audience?
Kirby (45:36):
Yeah, I think as I've talked to people about these results, first of all, it's really fun to do good applied research like this. It's fun to be able to talk about it because people can use it right away. So I would say consider if you, if you have clients or RFRM that has inventory, inventory challenges, I think consider the amylase enhanced gene as an approach to bridging that gap from year to year. And I also think, don't shy away from dietary starch, if you've got quality forages and quality feeds, 'cause this study showed you get a bit of an enhancement in the gross feed efficiency. The body weight change takes some of that away. But you get a little more of milk per unit of feed intake, which is important. And I have a gut health interest and an animal health interest.
Kirby (46:17):
And I think what I was worried about is that the increase in dietary starch might cause some subclinical inflammation and we don't see an ounce of that. And Barry and I actually wrote a review on that topic too, about starch and, and gut derived inflammation. And we just don't see the data for that yet. So don't shy away from starch 'cause you have an animal health concern. It's gonna drive production, drive energy into the cow. And it's something I'm hoping to investigate more as I start down in Ohio State. Got a few ideas for studies to kick that off. And the last thing I would say is come January 8th, if anyone has anything I can do to help them from Worcester, Ohio, please make sure to reach out.
Speaker 5 (46:55):
Yeah, good.
Kirby (46:56):
And Bill, can you put a bow on this one for us?
Kirby (46:59):
Well, first of all, you need a scarlet sweatshirt. Getting loose, most important, change your wardrobe. But, and I, as Curry was talking, I forgot one very important thing, the way you increase starch is you took out Zoey halls, you didn't take out port. And that's I think one explains a lot of why you didn't see any negative problems. So it's substitution, not just concentration. But I think what this study shows is, you know,
Bill (47:29):
Hybrid selection or corn silage selection affects the herd for 12 months. So that 's one of the most important decisions a farmer and a nutritionist gonna make. And I think what, what Kirby was talking about, there's a lot of things that go into this. And it might be just this, this silage may only benefit for, for three months or, or one month. And that has tremendous benefits. So you, you can't just look at papers and say, okay, this didn't do anything or this did something. But think about the whole picture. And again, as these the silage ages, we know it changes a lot. And if, if this product actually would allow you to start feeding this stuff at Green Shop or, you know, a week or two without this, this drag of tehran silage transition that has a huge economic benefit, even though if it has no effect the next 10 months, it it, that first month or two, if it affects it, it's a huge benefit.
Scott (48:29):
Yeah. Great advice. Bill. Bill, I want to thank you for another great topic and an even better guest. You know, Kirby, you've been outstanding. Wish you the best of luck as Clay has said in, in your new position. And want to thank you for coming along with us. Clay, it's always a joy to have you here at the Real Science Exchange. Loyal listeners, we appreciate you. We thank you for sharing this evening with us. We hope you learned something. We hope you had some fun and we hope to see you next time here at Real Science Exchange, where it's always happy hour and you're always among friends.
Speaker 5 (49:06):
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