 All right, we're going to get started for the second half of the morning session. Our first speaker is Dr. Christensen. She's a research animal scientist at the ARS Station Northern Great Plains Research Laboratory in Mandan. Dr. Christensen works with a multidisciplinary team of scientists to develop ag management practices for the Great Plains. Her work centers are on overcoming limitations to livestock production while maintaining or enhancing environmental quality through quantifying forage and feed management effects on livestock growth efficiency and determine, she wrote a long sentence here, and determine effects of various practices on controlling the spread of invasive species and grasslands with the subsequent nutritional effects for livestock. Her efforts will lead to the development of land and livestock management practices that will enhance agricultural sustainability. Dr. Christensen received her bachelor's degree in genetics and cellular physiology and animal science at BYU and her master's in PhD in dairy management and ruminant nutrition and physiology at Utah State University. She enjoys spending time outdoors with her family, gardening, and exploring the vast western landscapes of the US. So let's welcome Rachel. Thank you very much. Okay, so my presentation is kind of the oddball one because this is mostly livestock nutrition, but we thought it would be in good here to kind of think of the overview of where these grasses end up being used in livestock and kind of some thoughts that we should have underlying them. So, oh, let me talk a little bit about my co-authors. David Toledo spoke yesterday. He's here. He's a rangelandy college at the station. And then Dr. Swanson, Mihan, and Daelyn are from NDSU. They're the livestock nutritionists and beef grazing specialists. So a lot of the underlying historical and averages come from some of their work and their data. So this, of course, is what we're dealing with is invaded rangelands. And this study focuses mostly on the Kentucky bluegrass. And now more than ever, we need to get more out of these forages from a producer perspective. They're under a lot of stress economically with the increased cost of input. And so minimize how much needs to be input into a livestock operation. We need to maximize the forages that are there. So what we wanted to do was, okay, let's look at this Kentucky bluegrass. We have it. What's in it? How can we best utilize what we can get out of it? So we examined this nutritional quality. And then related that to what a cow, calf pair needs throughout the growing season. And so how we did this was we have two different pastures. And we had plots that were ex-close from the grazing animals. And then one of each pair of plots was mowed and one was not mowed. And so that mowing can simulate defoliation or any other kind of burning or whatever that could happen and then see the differences in responses between what was mowed and what was not mowed. And then we took these samples, we dry them, ground them, analyze them for nutrients. And then we put these nutrients in the model, a nutrition model that helps explain, kind of predict how the animals will respond to those nutrients and if those nutrient levels are appropriate for that type of cow. So you can see more of the clipping and how we collected those samples. So we lucked out that we got two different years doing this. The first year 2007 was a dry year. And you can see how it was about roughly half of the historical mean rainfall. And then 2018 was a little more normal, but still a little bit under, but we're kiling this a normal year. And then there's two different types of management, as I mentioned before, mowed and unmowed. And then for our model, so we use what the North Dakota state average cow is. So the average cow is, oops, sorry, the average cow is a Cemental Angus Cross, four years of age, with a 1400 pound body weight and then body condition score of five. So that's your average size cow of what's being put on the range lens. So our results were, and let me kind of explain how these graphs work. So in these graphs, the blue bars represent the amount of energy that is from the pastures. And then this green line up here is what the cow required. So you can see in this drought year that what the cow required was not met at any point in the year by the Kentucky bluegrass. The same thing with a mowed, in a mowed plot versus unmowed, you can kind of see there wasn't really a whole lot of difference, but maybe more of a decline in the unmowed plot. So then for 2017, the cow also has a protein requirement. And so again, you can see here that what the cow, what the pasture provided in these blue bars did not meet what the cow required throughout the season. Same thing with mowed. You can see that the mowed kind of dropped off faster in this year. And so that's kind of something that we picked out. So for 2018, so this was our normal year. Again, you see that the cows requirement, sorry, the cows requirements were not met by what was provided in the pasture. And you see just this gradual decline throughout the season for the energy. Same thing in mowed, though it was more sustained. They didn't change as much in a mowed plot as it did in the unmowed. So in 2018, the protein, you can see a lot more different effects from the mowed versus unmowed plots. So here again, the cow required two and a half pounds at the beginning of the season down to about 1.75 pounds per day of protein. And it wasn't met by the pastures. So we can see here that if these aren't met, then the cow would need to be supplemented ideally to meet all of the production goals of that producer might have. So the takeaway was the forage quality in these invaded pastures did not meet the needs and decline throughout the year. And so you would need supplementation programs to meet the needs of that cow. And you would use the nutrient need nutrient requirements to guide your decisions on what you would want to supplement with. And if we can get a nutrient secrecy and room inefficiency, then you can see the performance increase. So how do we do that? Here's some suggestions. We have to manage around the pasture and the nutrient content. So I mean, the drought year we founded that we probably shouldn't be grazing too early because that could affect the subsequent months and the nutrients that are there. And so be aware of those consequences of early season grazing and maybe not hit it as hard so that you have some nutrients there. But when we know what our nutrient mineral levels are versus when we can supplement, then we can maximize how much we will supplement to make up those differences in those nutrients. And then can low input so low input means pretty much not supplementing or supplementing with expensive supplements. So can we still get our desired gains or maintenance if we have a low input situation? So that's what we do at our station is we kind of focus on more low input strategies to meet the needs of the cattle. And so one of the things that we do at our station is we breed for a smaller body weight. And so our average mature cow size is a 1200 pound cow. And we also cross breed. So we have an Angus Herford cross breed. So that makes a little more smaller body cow and maybe a little more efficient with the nutrients that are there in the pasture. So that same model that we use, the nutrient model instead of having a 1400 pound cow, we put in a 12 pound cow or 1200 pound cow, four years of age Herford Angus cross, then we have a lower required plane of nutrition. And so now this they switched it on, switched it a little bit on you. But this now is what the pasture is supplementing or providing. And this is the cow's nutrients. So you can see that as the pasture declines, when this cow requirements are the highest, they're still being met. So the pasture nutrients decline over time. The cows requirements are more closely met than they were in those the other situations. So if we have a smaller body cow, she can handle the low requirements in the pasture better than the larger body cow can. And the same thing for a normal year, you can see that the pasture nutrients are declining, but the cows requirements are more often met with the smaller body cow. So basically the take home message here is we need to match the cows genetics to the pasture nutrients, because it's easier to change that to use a change your cow genetics and it is as we have seen throughout this conference to change what's in your pasture. So if you do need to supplement, here's some things that are often used to supplement. They're all listed by TDN, which is Total Digestible Nutrients. And you can see that most of them are in about the 60-70 range. We want to aim for about a 60 TDN. And so if we supplement with these higher TDNs, kind of balancing out what's already there in the pasture, then we can get a greater amount of nutrients for the cow. A range cake is often fed. When I do put it in the model, I get a 48 TDN, which isn't very high. And some of them are being advertised as having 77 TDN. So I'm not sure what's, you don't, they don't really tell you what's in a range cake. So you have to be careful with what's in there. And then the economics supplementation. The take home message on this, so this is using our market, market prices. And these were from FeedMix in central North Dakota. And the levels of protein, the levels of energy. And then if you do on a cost per ton of crude protein, this is just a way to compare them for the nutrient that you may be looking for. This can tell you what the best value is. So distillers is the best value for crude protein. And then crack corn is the best value for energy. So a producer can use this to decide what the best option would be to supplement and then to see the levels of protein or nutrients meet the needs for his cows. Another thing to consider is the mineral content of these pastures. And we're still working on the data from this. So we took the mineral content from those same plots. And up here you can see by across the season, the blue bars are mowed for the drought year. The orange bars are unmowed for the drought year. The gray bars are mowed for the normal year. And the yellow bars are unmowed for the normal year. And this line here is the requirement for how much phosphorus is consumed per day. And so you can see that some the early months, this one's calcium down here, the early months, the mineral content is met and the late months is met. But those middle months, which are your key months for peak lactation and preparing that cow to be bred again, you can see that those minerals are not being met. So almost everyone puts out mineral anyway, but maybe one way to consider reducing costs would be we don't really need to supplement them during these periods, but we do in this period. That's one way to save money is just knowing where you're at on your mineral levels for the season and then supplement appropriately. And then of course to promote diverse pastures. So on a nutritional basis, what does this mean to our cows to have more diverse pastures that have more native or warm season grasses in them? So we know that it slows growth in the summer or goes into dormancy, depending on the moisture, but switch grass, blue stem, blue grandma, you know, all of these other ones are heat tolerant and they will stay more, stay higher in nutrition and in biomass during that slump when your blue grass tends to to taper off. And previous research has shown that steers gained more weight per day and more beef per acre on warm season grasses compared to we'll see them. So that's another thing to consider and it even though it's a lot more work to restore a pasture, it's actually cheaper than supplementing with feed. So here's the nutrition of the warm season grasses compared to the Kentucky blue grass in some of the plots that we we've done some studies on. So this is kind of a middle of the road Kentucky blue grass. And what we want is the high the TDN is kind of all of the digestible nutrients put together. So blue grandma and blue stem are higher than Kentucky blue grass. And then these are a little bit lower but not as much not too different from Kentucky blue grass. So your nutrition profile will be about the same or better if you have more native species in your pastures. So another plug for improving our native species content in our pastures. And so this just goes to show that if you know what your pasture is providing, then you can better meet the needs of your cattle and make better decisions especially in a market where supplementation is expensive. I'm matching your genetics to your pasture is really crucial. And then evaluating the protein and energy supplements by cost will help you make better decisions because you can meet your cattle nutrition requirements with the most economical feed option and optimized performance. And this is all of course beneficial to the bottom line because we can get more productive beef animals from meeting the nutrient needs that they have. And that's all.