Data Distillations
Data Distillations utilizes Rock River Laboratory’s vast database of feedstuff and agronomic information from across the United States, along with our expert team, to share important insights, quarterly.
Keeping the agriculture industry in front of challenges and opportunities with available feedstuffs and agronomic trends is pertinent to farm success. With this in mind, we share relevant data, distilled into graphics and highlights, along with what our team members are gleaning. Prepare for and remedy the peaks and valleys of feedstuff components with the help of another set of eyes. Plus, understand trends to date and be ahead of the curve of soil fertility.
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December 3, 2024
Author: John Goeser, PhD, PAS
A Cleaner 2024 Crop Coming Into View
With the 2024 growing season now well behind us, the corn silage and grain hygienic quality is coming into focus. In years past, ear and stalk rot issues during the growing season equated to mold, spoilage yeast, mycotoxin and feed hygiene concerns. These contaminants are known to negatively affect animal health and performance. The start of the 2024 growing season was exceedingly soggy for many, with plant disease concerns on the mind. While this was another year for the record books in some areas, drier weather following pollination and through ear-filling periods equated to tamped down ear and stalk rot from the Midwest through the Northeast. The resulting mold and mycotoxin contaminant levels in the 2024 corn silage crop appear to be muted on the whole. Figure 1 showcases Vomitoxin levels (Deoxynivalenol; DON), as a signal mycotoxin contaminant in the popular forage crop. Vomitoxin is known to negatively affect animal health, rumen and digestive tract performance, and suppress the immune system.
Figure 1: Corn silage vomitoxin (ppm) results for 2021 through 2024 crop years, of samples analyzed by Rock River Laboratory, Inc. in the Midwest and Eastern US regions.
Rarely are single mycotoxins present in forage or grains. Alternatively, multiple different mycotoxin contaminants, at different concentrations, may be present. Hence, producers and nutritionists should use mycotoxin analysis panels, including measuring multiple mycotoxins for a more robust feed mycotoxin evaluation. Expanding to also evaluate Zearalenone trends, Figure 2 details notably less contamination for this mycotoxin as well. Zearalenone is known to negatively affect reproductive performance in livestock.
Figure 2: Corn silage Zearalenone (ppm) results for 2021 through 2024 crop years, of samples analyzed by Rock River Laboratory, Inc. in the Midwest and Eastern US regions.
The red lines within both Figures 1 and 2 detail a benchmark adapted from researchers and scientists. The Rock River Laboratory, Inc. mycotoxin benchmark guideline is available here.
Producers and nutritionists should consider other feed contaminants beyond mycotoxins - such as spoilage yeast or negative bacterial contamination. The former is an underrecognized issue with silages, and can disrupt rumen metabolism and dairy or beef herd performance. Spoilage yeast are a seasonal issue for silages, with clear seasonal trends in contamination or activity levels. Figure 3 highlights the annual trends in silage spoilage yeast contamination, as measured by Rock River Laboratory, Inc. This negative feed hygiene issue is likely of greater concern than mycotoxins for 2024 crop corn silage.
Figure 3: Corn silage spoilage yeast (CFU/g) results for 2021 through 2024 crop years, of samples analyzed by Rock River Laboratory, Inc. in the Midwest and Eastern US regions.
October 2, 2024
Author: Cliff Ocker
The Dirty Truth About Straw
Adding straw to our herds’ rations can help dry down a wet diet, slow the rate of passage, stimulate the rumen, or improve rumination. Plus, straw can be used as a filler to keep animals from eating more energy-dense forages, or even help to stretch other forages.
However, adding straw may bring more into the diet than you bargained for. Recently one of our clients called to review the feed hygiene report that they had requested on a straw sample, which was quite dirty. At the end of the call, they asked the question: is all straw this dirty or just mine? This made me curious, and I began searching our database to see how ‘hygienic’ straw actually is.
The results were a bit shocking, and while our straws inclusion rate is quite low in most diets, it can introduce many unwanted anti-nutrition factors into the diet. Mold and yeast levels tend to run higher than expected in straw but mycotoxins and enterobacteria are often found as well.
The pie charts here (Figure 1) show the prevalence of several levels of mold and yeast on all straw samples analyzed at Rock River Laboratory over the last four years. Note that 75 percent of all samples contained both mold and yeast levels greater than 100,000 CFU/gm. Vomitoxin has been found in about 50 percent of the straw samples analyzed for mycotoxins and the current average is about 0.7 ppm, as noted in Figure 2. While not as prevalent, enterobacteria, when present, averages 337,498 CFU/gm.
Figure 1: Levels and prevalence of hygienic challenges in straw
Figure 2: Four-year trend of DON levels in straw
Consider which diets contain straw: far-off dry cows and pre-fresh animals may be receiving straw as a filler. These animals are stressed already as they grow a calf and prepare for high levels of production. Fighting additional hygiene factors may not be the best for their immune systems or their calves.
Of note, the grains coming from these small grain crops may contain challenges as well. Wheat grain in particular, has shown much higher levels of DON (Vomitoxin) this year than in previous years. Looking at our Rock River Laboratory data, the current average level of DON in wheat grain is just over 1 ppm. Beware of an accumulation effect if hygiene issues are present in other feedstuffs.
Depending on the group of animals being fed and the inclusion rate, it may be good to check the cleanliness of your straw before adding too much to the diet. What’s hiding in your straw?
August 7, 2024
Author: Katie Raver
A Pain in the Ash
Although we tend to focus on major nutrients such as crude protein (CP), starch, or Neutral Detergent Fiber (NDF) and their respective digestibility when assessing a nutrient report, ash is also an important analyte that should not be overlooked. High ash in feed can be a concern for a variety of reasons. One being that ash does not have an assigned energy value, so despite minerals that make up ash being essential to animal performance, ash in and of itself does not contain energy from a caloric standpoint. In fact, ash is not considered at all when we look at the Total Digestible Nutrients (TDN) equation . With this in mind, feeds with higher ash content tend to have lower TDN values.
Looking at silages, high ash levels can be an even larger concern as they can be a sign of forage dirt contamination. While some ash is unavoidable [after all, plants do naturally contain minerals], too much ash can be indicative of excess dirt getting picked up in harvest. This can be caused by rain splashing dirt on lower leaves, raking of swathed crops, or cut height, to name just a few. In some cases, too much dirt in forages can act like a buffer and interfere with the natural ensiling process, making it difficult to reach the optimum pH. Typically crops that are subject to a swathing or raking process are more likely to carry higher than average ash content. Figure 1 below shows a trend for increasing pH in haylages, mixed forages, grasses, and small grains silages as ash levels increase. Higher pH may interfere with silage stability over time and can increase the risk for other anti-nutritional factors that negatively affect the silage.
Figure 1: pH vs ash content (%DM) in various silage types
Another concern with high ash silages is potential clostridium contamination. Clostridium bacteria naturally live in the soil, however proper ensiling conditions help keep them at bay. The bacteria have the potential to cause serious health issues in cattle. When clostridium growth in silage results in butyric fermentation, butyric acid at high enough levels can lead to palatability and dry matter intake issues. Figure 2 below shows an increasing risk for high butyric levels as ash level increases. Note, high ash does not always indicate the presence of clostridium or butyric fermentation, as there are many silages represented that have high ash without butyric fermentation.
Figure 2: Butyric acid vs ash content (%DM) in various silage types
The challenges ash creates from a silage stability standpoint are also apparent from a fermentation shrink standpoint. This estimate of fermentation shrink is predicted using the equation by Goeser et. al., 2015 which uses silage nutritional parameters and fermentation. Figure 3 below demonstrates that as ash levels rise potential for shrink due to inefficient fermentation also rises. This represents a loss of usable nutrients and feed available.
Figure 3: Fermentation shrink vs ash content (%DM) in various silage types
When possible, management practices should be designed around minimizing excess ash contamination, especially in ensiled forages. This will help decrease the risk of poor fermentation, and less-than-ideal feed hygiene.
July 30, 2024
Author: Scott Fleming, CCA, TSP
The PSNT Post-Season Crystal Ball
Nitrogen recommendations can be tricky in a normal cropping season. Throw in the wild weather of 2024, and establishing sidedress rates can feel like throwing darts blindfolded. Now that sidedress season is over, it’s time for a data roundup to see where the numbers fell. The University of Wisconsin (UW) breaks results into six categories. The numbers in Figure 1 are the units of nitrogen to credit, based off the Pre-Sidedress Nitrate Test (PSNT).
Figure 1: University of Wisconsin Nutrient and Pest Management (NMP) Program Soil Nitrate Test for Corn Production in Wisconsin, Nitrogen Fertilizer Recommendation Adjustments, Based on PSNT Lab Results.
Soil nitrate results are captured from the Rock River Laboratory database of all soil samples arriving during the 2024 sidedress season. Figure 2 shows the frequency of nitrate results falling into each of the UW’s categories. Interestingly, about half of the samples arriving at Rock River Laboratory fell into the lowest category. Obviously, this is only a tiny snapshot of all fields in the state of Wisconsin and not a broad look at current soil nitrates. But it is interesting nonetheless!
Are growers sampling fields they have a hunch are low and validating their knowledge with data? Are growers applying a reduced rate of nitrogen at planting and using the PSNT to assess crop demand? Is the heavy rainfall causing lower than anticipated PSNT levels? I have a hunch that all of these considerations are coming into play. We will likely never know for sure, but it is a great conversation starter.
Figure 2: 2024 Pre-Sidedress Nitrate Test Frequency Distribution, Based on Rock River Laboratory, Inc.'s Database.
