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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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.
April 9, 2024
Author: John Goeser, PAS, PhD, Diplomate ACAN
Corn Grain Quality Ranges Substantially
Corn is often regarded as a commodity, however yellow number two corn contains a notable range in nutrient content and quality. Purchased corn must meet certain quality thresholds, though high-quality corn far exceeds the yellow No. 2 quality thresholds. The resulting range in shelled corn quality is likely due to several factors, such as the growing season or region the crop was grown, contributing sizable variance.
Delving into Rock River Laboratory’s database uncovers meaningful nutritional variation present in yellow No. 2 corn, which may not be readily recognized by dairy or beef producers and their nutritionists.
Crop year and growing conditions clearly influence corn grain quality, with notably different starch levels evident in the 2023 Midwestern and Western regions relative to the prior two crop years (Figure 2). The regions’ starch content moved in opposite directions.
The region where corn is grown also appears to impact nutrient content. Starch content is substantially greater in the Midwest region, but notably down for the Western region.
While starch content drives the energy value in corn grain for dairy or beef producers, protein content and rumen starch digestibility also impact feeding value (Figures 1 and 3). Protein content is known to interact with rumen starch digestibility, and greater protein content correlates to harder grain, higher test weights, and lesser rumen starch digestibility. This is visually evident when contrasting the Midwest and Western regions. Higher protein content for Western corn grain samples corresponds with lower rumen starch digestibility, relative to the Midwest region.
In summary, corn grain nutritional quality likely deviates substantially from feed library book values due to many different variation contributors. The range in starch content and rumen starch digestibility evident within these database summaries may be nutritionally relevant.
Figure 1: Shelled corn protein content, % of DM, for crop years 2021, 2022, and 2023 in samples submitted to Rock River Laboratory for Eastern, Midwestern, and Western regions.
Figure 2: Shelled corn starch content, % of DM, for crop years 2021, 2022, and 2023 in samples submitted to Rock River Laboratory for Eastern, Midwestern, and Western regions.
Figure 3: Shelled corn rumen starch digestibility, % of starch, for crop years 2021, 2022, and 2023 in samples submitted to Rock River Laboratory for Eastern, Midwestern, and Western regions.
February 1, 2024
Authors: Cliff Ocker and Katie Raver, MS, PAS
Is Hygiene Holding Your Herds Back?
Feed hygiene is often overlooked when troubleshooting and reviewing what might be holding a herd back. By hygiene, we are referring to the anti-nutritional components in our feedstuffs. This can include mycotoxins, mold and yeast, enterobacteria, salmonella, and clostridia among others. While many times we check for one or two of these detriments, keep in mind the accumulative effect of several of these can mount - especially on our more stressed animals.
Now that we are well into feeding the 2023 crop, we see some trends emerging that are worth considering. Vomitoxin (DON) seems to be one of the heightened factors moving into 2024, particularly when evaluating data from the Eastern US.
Figure 1. DON Levels for the Eastern US Over the Last Year
When comparing potential sources of vomitoxin in the eastern US vs Midwest, ear corn, shelled Corn, dry distillers, and corn silage are at the top of the list in both regions. However, overall levels in the east are higher than those observed in the Midwest, and overall ear corn levels look similar across regions. These samples with high vomitoxin seem to be widespread across the northeastern US and Midwest, with no one distinct area standing out as a “hotspot”, as shown in Figure 3.
Figure 2: Level of DON by Feedtype, Eastern US
Figure 3: Level of DON by Feedtype, Midwest, US
Figure 4: East and Midwest US, Location and Levels of DON
Similar to DON levels, we are seeing an uptick in the levels of Enterobacteria in certain parts of the US. Figures 4 and 5 show different areas of the US and the associated increase in the level of Enterobacteria in recent months. Enterobacteria are a class of gram-negative bacteria, typically associated with the GI tract and most commonly introduced into feed through manure contamination.
Figure 5: Enterobacteria Levels in All Feeds from Across the US Over the Last Year
Contributing factors of enterobacteria in the diet from data across the US (n sampled > 10) include small grains silage, corn silage, legumes, and shelled corn. Although the majority of the feeds listed in these tables are ensiled, dry feeds can also be a potential source of Enterobacter as well.
Figure 6: Levels of enterobacteria by Feed Type
If you feel that hygiene items may be affecting on-farm performance, feel free to reach out to our team., We offer feed hygiene packages or individually test for areas of concern. We can also provide data showing the prevalence and levels that we have found in feedstuffs across the US.