08/19/21 Sound Ag Advice 433

Faced with poor corn yields due to drought, some producers have begun harvesting corn for cattle forage instead of grain. Zac Carlson, NDSU Extension beef cattle specialist joins this week’s Sound Ag Advice to discuss the pros and cons of using drought-stressed corn as a forage source.
Speaker 1: Kelli Anderson, NDSU Ag Communication Specialist
Speaker 2: Zac Carlson, NDSU Extension Beef Cattle Specialist

Kelli: This is Sound Ag Advice, a weekly feature presented by NDSU Extension. I'm Kelli Anderson. This week we're going to be talking about alternatives for harvesting drought-stressed corn. Again, drought conditions across much of North Dakota have created some major issues for livestock and crop producers, and many are facing support conditions. 

Today, I've got Zac Carlson NDSU Extension beef cattle specialist to talk about some of those alternatives for harvesting corn. So Zac, before a producer decides to harvest their corn for forage. What are some things they should do first?

Zac: Great question, Kelli. The first thing they need to check is to make sure that those crop acres are certified to be harvested. So, check in with your crop insurance adjuster and make sure that you are meeting all qualifications prior to going into those fields in harvesting so that you meet all insurance qualifications for that. A second would then be to check your chemical labels for those herbicides that you've applied to those fields. Oftentimes, these chemicals come with restrictions and they'll be posted on their label. 
There is a great guide, it's the NDSU publication, Weed Control Guide 2021. Pages 109 through 112 list the common chemicals found, and then the grazing or harvesting restrictions on those in days from application. So be sure to check there, before entering into the field and taking these forages.

Kelli: So, Zac, you have a recent news release that mentioned some concerns with harvesting corn, especially corn is drought stressed, which we've seen a lot of. What are some of those concerns you might have for harvesting drought-stressed corn?

Zac: A lot of drought-stressed plants can become nitrate accumulators, and corn is one of those. So, in situations where the growth of the plant is stunted, whether that's a frost that we're familiar with, or in this case, we're dealing with drought, the nitrates will tend to accumulate in the plant and they accumulate and are more concentrated closer to the ground. So from the stock, and then they get less concentrated as they move up the plant. So be sure if you're considering harvesting or grazing these that you take a representative sample from your field. So that would look like several areas of your field and be looking out for short corn, tall corn plants, dry, maybe lush. Take all a sample from all those at the height that you intend to harvest, or if you're grazing then go ahead and take that plant. And then the Vet Diagnostic Lab here at NDSU can analyze those samples or you can send them off to a commercial laboratory and get an analysis of nitrates. So combining those samples together, chopping it up in any way that you can and mixing it in. And if you need help with this, your NDSU Extension agent in your county, would certainly be willing to help you out in getting these processed, as well as submitting to a lab.

Kelli: One final question, if a producer would like to turn their cows out to graze standing corn, what are some of the things they should keep in mind? 

Zac: Yeah, so if we're talking about grazing, we're going to again be talking about nitrates, having that analysis in hand, and knowing what your nitrate content is in the field, will help you as you can adapt cattle to higher nitrate levels. But it's important to know what you have before going out and grazing. 

So, understanding what your nitrate content is, and then really, essentially, with grazing considerations on nitrates, you want to ensure that you're not forcing cattle to eat that lower portion of the stock so having a lighter stocking rate in those fields will allow those cattle to select the ear, leaf and husk which we know they typically do and the upper portions of the stock without going to those heavier concentrated areas of nitrates. So, like stocking lightly. 

The other thing we want to be aware of is, although there may not be a lot of grain fill this year, and a lot of our corn fields that cows that have previously grazed, those cows will be more likely to target ears of corn when they get into those fields, so if you have fields, that did have some ear development and some grain fill, then you want to be sure that you're keeping a close eye on how those cows are behaving and acting and grazing. Just to ensure, once again, that you have lightly stocked that field. And, again, kind of moving from a low nitrate or low nitrate-concentrated fields. 

And then you can kind of move those cattle through into some higher-nitrate content fields. It may be also, as it's always recommended, whenever grazing to turn cattle out, not hungry. So make sure that you've been providing feed in large amounts so that these cattle aren't hungry two to three days prior to grazing. So that will allow those cattle to not overeat in those first initial days and give you consequences in both possible acidosis through grain overload, if that's the case, or nitrate poisoning through high-nitrate content feed. So just make sure that those cattle aren't hungry when they're going out. 

Kelli: Thanks for your information today, Zac. Our guest today has been Zac Carlson, NDSU Extension beef cattle specialist. This has been Sound Ag Advice, a weekly feature presented by NDSU Extension. 

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