Data Distillations header image Data Distillations

Data Distillations is published quarterly and utilizes Rock River Laboratory’s vast database of feedstuff information from across the United States, along with our expert team, to share important insights.

In an effort to help the agriculture industry stay in front of challenges and opportunities with available feedstuffs, relevant graphs will be shared, along with what our team members are gleaning based on those graphs. Prepare for and remedy the ups and downs of feedstuffs components you utilize in your rations with the help of another set of eyes. Sign up to receive alerts when new Data Distillations are available each quarter by completing the thirty-second form at the bottom of this page or click the link here

March 18, 2022 Insights

Author: John Goeser

Mid-spring fecal starch database still suggests opportunity

For the Northern Hemisphere, corn silage and high moisture corn have been in the silo for six or more months. Based upon available experience and data from years prior, we understand that starch digestibility improves with fermentation. After six months, corn silage and high moisture corn should be feeding closer to their full potential as opposed to freshly harvested corn. However, 2022 has proved different. Starch digestibility is still likely an opportunity for many dairy and beef farms. 

Fecal starch measurement has been a valuable tool - having learned from Dr. Ferguson and Dr. Hutjens over the past decades that more grain and starch in manure equates to less digested grain by dairy and beef cattle. The goals for dairy and beef fecal starch levels are less than 1 percent and 3 percent of manure dry matter (DM), respectively. These goals correspond to the top 15 percent of samples analyzed by Rock River Laboratory, Inc. 

This year, many dairy farms still appear to be well above 1 percent,  as visualized in Figure 1. The green line indicates the goal at 1 percent of DM, and some dairies appear to hit the goal. However, the orange line indicates 3 percent of DM, which has historically been considered the benchmark. If we use the Fecal Starch Calculator app available from Rock River Laboratory, assuming 55 pounds DMintake, 25 percent dietary starch, and evaluating the economic difference between three percent and one percent fecal starch at $7.50 per bushel corn, we can recognize the improved total tract starch digestibility at one percent fecal starch equates to roughly $0.07 per cow in wasted feed cost via undigested corn grain. 

Beyond silage and high moisture corn, dry shelled corn is also likely a contributing factor to higher fecal starch levels this year, with the 2021 crop yielding harder and less digestible corn. If dairy or feedyard performance is thought to be suboptimal, consider investigating how much starch is contributing to the challenge by making fecal starch measures for your greater intake pens. With the current feed prices, the economic ramifications of suboptimal starch digestion are greater than ever.

Figure 1: Recent dairy fecal starch results, % of DM, for samples analyzed by Rock River Laboratory, Inc.

Graph of fecal starch percentages over time from March through April 2022

February 23, 2022 Insights

Author: Cliff Ocker

Forage Isn't the Only Source of Variation in the Diet 

Still using book values for commodities? Think again. As nutritionists, we try to do a pretty decent job of monitoring the forage changes on the farm. Often, we sample the new forage from a new crop year, or when we open a new bunker and we pull samples as the cows indicate that something may have changed. Yet, how often do we pull samples of the commodities that are being fed at the farm? Do we think they are always as book values suggest?

As we know, forages test differently from year to year based on a number of factors, including hybrid, maturity at harvest, and environmental conditions. Similarly, our commodities are derived from the same or similar crops and are also affected by some of these same factors and go through additional processing to become the ingredient that we feed on farm. Thus, our commodities tend to be just as variable as forages, and exclusive use of book values may be missed opportunity in terms of profitability on the farm.

Consider this: if the Dry Matter (DM) and Crude Protein (CP) are both two percentage points higher than book values on Soybean Meal (SBM), what does that mean at the farm level in both amount fed and profitability? If two pounds of protein are needed in the diet, from SBM, and DM = 90 percent and CP=46.5 percent, the amount fed/head/day would be 4.3 pounds as fed. Whereas if the SBM is 92 percent DM and 48.5 percent CP, the amount fed drops to 4.12 pounds as fed - a difference of .18 pounds/cow/day. This doesn’t sound huge but with the cost SBM, this is likely over 4 cents/cow/day on a single ingredient!  What if the same is true on two or three other commodities being fed? This could quickly become a 10 to 15 cent/cow/day savings opportunity.  What if the values are lower instead of higher and now there is also lost milk based on a shortage of nutrients?

While our book values suggest that most of our commodities are 88 percent DM, very few dry commodities in the Rock River Laboratory database are less than 90 percent DM, as noted in Figure 1 for DM on Canola Meal (CM). Note in Figure 2, the protein value changes in Canola year-over-year and the variation that we see in SBM for protein in Figure 3.  This type of variation can be seen on most commodities coming through the lab, making it especially important to monitor commodity variation. Adjusting for these variations, in commodities as well as forages, can improve profitability and productivity.

Figure 1: Figure 1: DM variation in Canola Meal over the past 3 years

Graph of dry matter variation in Canola Meal (CM) over the past 3 years from Rock River Laboratory's database

Figure 2: CP variation in Canola Meal over the past 3 years

Graph of Crude Protein (CP) variation in Canola Meal (CM) over the past 3 years according to Rock River Laboratory's database

Figure 3:  CP variation in SBM over the last 3 years

Graph of Crude Protein (CP) variation in Soybean Meal (SBM) over the last three years, according to Rock River Laboratory's database

November 15, 2021 Insights

Author: Katie Raver

Yeasts, Molds, and Mycotoxins, Oh My!

When cows suddenly start losing productivity or health events start to increase, we may often look at antinutritional factors as a potential cause. It’s easy to become overwhelmed with the sea of feed hygiene challenges that can impact feeds, however, by understanding regional and feed type trends it can help you strategically work through the situation - eliminating fear and stress. 

At Rock River Laboratory, we closely monitor antinutritional trends in different US regions to try and stay at the forefront of possible issues. We can also break these down by different feed types to help better identify what may be the underlying culprit of health or productivity issues. By monitoring these trends, it can help producers and nutritionists make decisions and complete appropriate testing before challenges arise and productivity is lost. 

Understanding the origin of these antinutritional factors can also be helpful in narrowing down the potential cause. For instance, when looking at enterobacteria, Total Mixed Ration (TMR) is often a common suspect. These are harmful bacteria to the cow that can stimulate a plethora of different issues. This is because TMR has the most opportunity for contamination with manure. However, silages cannot be ruled out as a carrier, depending on storage or harvest conditions. Extremely wet harvest conditions can be a risk factor for high enterobacteria levels. The graphs below highlight the potential for silage contamination, with some silages showing enterobacteria levels well over one million. Diluted in a ration, this may even go unnoticed until coupled with other immune challenges. 

Figure 1: Enterobacteria amounts in TMR samples


Figure 2: Enterobacteria amounts in silage samples

Mycotoxin (DON) levels and types can also vary greatly by region and type. For instance, in samples tested since 2018, corn byproducts such as distillers and gluten feed have shown DON levels above 1.5 ppm 84 percent of the time, whereas, in corn silage, DON was above 1.5 PPM 48% of the time. The net effect may be diluted by feed inclusion. However, understanding what feeds are most impacted can help us troubleshoot or better prepare for potential issues.  While we sometimes associate corn products with Aflatoxins, trends across feeds tend to respond similarly to environmental conditions. Understanding the type of fungal infection is responsible for different toxin production can also help to understand why and if feeds are impacted by mycotoxins at varying levels. 

Figure 3: Aflatoxin levels in different silages tested since 2018


Regional weather patterns can also have a big impact on which mycotoxins are present. For example, in early 2021, an increase in DON levels was seen in TMRs tested originating from the eastern US.


Figure 4: DON levels in TMR samples originating from the eastern US


Digging a bit further, this likely originated from a variety of corn sources - corn silage, corn grain, and corn byproducts. Growing conditions throughout this crop year have been extremely diverse domestically. Some regions experienced severe drought, while others started out in drought and had ample late season moisture. These conditions can lead to varied fungal and mycotoxin pressure. The mycotoxin guidelines below are one of many tools available to help evaluate levels and decide when further testing or action might be warranted. 

Mycotoxin guidelines

No feed is exempt from contamination with anti-nutritional factors, however, understanding trends can help us quickly and efficiently identify and resolve problems that may arise due to these contaminants. 


August 30, 2021 Insights

Author: Cliff Ocker

The Cost of Fermentation Shrink

Fermentation shrink, often referred to as Dry Matter (DM) loss, is real. Not many would argue that. And as we delve into the nuts and bolts of this phenomenon, we often talk about it in terms of percentages. But what if we assign a dollar value to fermentation shrink?

Dr. Limin Kung, University of Delaware, suggests that it is difficult to preserve a forage without seeing 10 percent DM loss. If this is true under the best conditions, how high does that loss value become for poorly fermented or poorly managed bunkers or drive-over piles?  Uniquely, Rock River Laboratory helps to try to find that answer. In 2015, Dr. John Goeser, Director of Nutrition at Rock River Laboratory, built an algorithm to calculate fermentation shrink based on the fermentation profile of individual forages. [For more information or to receive a copy of this peer-reviewed and published paper, please contact Rock River Laboratory.]

The fermentation dry matter loss (shrink) value is reported on all forages with a corresponding fermentation analysis. Note Table 1 which shares averages and ranges across feed types. Bear in mind that the fermentation shrink represents only a portion of the total shrink and the total losses are likely greater than what is reported on our Rock River Laboratory Report. This is simply because we solely use the fermentation profile to predict this value and it does not include environment and management items that could significantly add to this value.

Tying the fermentation shrink value back to dollars hit me a few years back when I was asked to help do pre-harvest meetings on a few large dairies. During the discussion of bunk management and reviewing how much silage was pushed by the pack tractor after truck unloading, we realized quickly that an additional tractor was needed to achieve the proper density. With some resistance to the need for a second tractor (because of costs), someone asked the cost of NOT adding the second tractor. 

Without knowing exactly what additional DM would be lost, what if we can improve fermentation shrink by three percent?  For the aforementioned dairy, it meant that they would need to plant an additional 150 acres of corn. The owner of the dairy proceeded to share that the additional costs associated with 150 extra acres of corn would cost him in excess of $200,000. A second pack tractor was promptly added. 

For most dairies, three percent shrink may not mean that 150 additional acres of corn silage are needed. But the fact remains that fermentation shrink typically equates to a larger dollar amount than we think. Helping a dairy or feed yard realize the true cost may help prompt more open discussion around bunk management and the use of a well-researched silage preservative/inoculant. Checking fermentation shrink is often not an additional cost as it comes as part of several Rock River Laboratory NIR packages. 

While fermentation shrink is real and quite costly, a few tips can help reduce this challenge. Try to put up a 'clean' feed. As seen in Figures 1 and 2, while ash content increases, so does DM loss. Ash acts as a buffer and elongates the fermentation process - increasing DM loss. Keeping ash/soil contamination out of forages will help in the fermentation process. Moisture also plays a huge role in how a forage will ferment. Figures 3 and 4 showcase how the higher levels of moisture lead to a more inconsistent fermentation and DM loss. However, depending on the storage type, the moisture level needs to be high enough for adequate packing to reduce oxygen levels in the forage. Reviewing management practices prior to harvest of any feed type can pay big dividends in reducing DM loss.

Table 1:  Fermentation shrink averages and ranges across feed types

Feed Type 15th Percentile Mean 85th Percentile Standard Deviation (SD)
Haylage 2.079 3.224 4.287 1.684
Corn Silage 1.383 2.448 3.472 1.980
Small Grain Silage 1.954 3.982 5.150 4.472

Figure 1: Fermentation shrink vs. dry matter for hay

Higher ash content in forage increases fermentation shrink. 

Plot of Fermentation shrink vs. ash in hay from Rock River Laboratory samples

Figure 2: Fermentation shrink vs. dry matter for small grain silage

Higher ash content in forage increases fermentation shrink. 

Plot of Fermentation shrink vs. ash in small grain silage from Rock River Laboratory samples


Figure 3: Fermentation shrink increases as soil (ash) contamination increases in the hay crop


Plot of fermentation shrink vs. dry matter in the hay crop from Rock River Laboratory samples

Figure 4: Fermentation shrink increases as soil (ash contamination increases in small grains silage) 

Wetter forages may require more management as Rock River Laboratory data demonstrates less consistency around fermentation shrink as forages are put up with higher moisture content. 

Plot of Fermentation srhink vs. dry matter in small grain silage from Rock River Laboratory samples;

July 19th, 2021 Insights

Author: John Goeser, PhD, PAS, Dipl. ACAN

Nitrate Content Questions and Database Trends

The building block for amino acids and protein in plants is nitrate-N. Think of the plant as a factory in this regard. The protein production within the plant is typically seamless when the plant has moisture and energy. However, with stressed plants,  there may be an accumulation of nitrate-N that was not incorporated into protein within the plant. Stress can occur through drought or freezing conditions. In drought conditions, particularly after a rainfall event, plants will readily absorb nitrate-N but may not have the energy and resources to build protein. In freezing conditions, the plant dies in its current production state, and unused nitrate-N is stuck within the plant. 

In either case, nitrate-N can become a concern for animal nutrition. Nitrate-N is toxic to ruminants if the concentration within the total dietary intake exceeds the rumen’s ability to metabolize the compound. Dairy and beef cattle can adapt to increasing nitrate-N concentrations in the diets, provided the nitrate-N concentration increases gradually. However, as a rule of thumb, forage and ration content greater than 1,000 parts per million (ppm) begins to be of concern and should be monitored. Nitrate-N concentrations of up to 4,000 to 5,000 ppm have been measured over the past several years, however many samples are less than the 1,000 ppm concern threshold. 

With drought conditions in the Midwest through to the south and western US, nitrate-N concentrations are being evaluated. Sorghum and other small grain silages are drought-friendly crops, however, they have also been known to accumulate nitrate-N. Figure 1 showcases the nitrate-N concentrations for populations of sorghum and small grain silages samples analyzed in four consecutive crop years. The three vertical black lines within each bell curve represent the 15th, mean and 85th percentiles, respectively.  A majority of the samples are less than 1,000 ppm, however, roughly 15 percent of samples are near 2,000 ppm. The average nitrate-N content this growing season appears to be slightly greater than the prior two years. 

Figure 1: Nitrate-N concentration for sorghum and small grain silage samples analyzed by Rock River Laboratory, Inc. the past four crop years.

Figure 1: Nitrate-N concentration for sorghum and small grain silage samples analyzed by Rock River Laboratory, Inc. in the past few crop years.

In Figure 2, similar graphics detail the nitrate-N concentrations for hay crop samples throughout the US over the past four growing seasons. Hay crop samples are substantially less contaminated than the sorghum and small grain silage samples.

Figure 2: Nitrate-N concentration for hay crop samples analyzed by Rock River Laboratory, Inc. the past four crop years.

Figure 2: Nitrate-N concetration for hay crop samples analyzed by Rock River Laboratory, Inc. over the past four crop years.

If your forage turns out to be high in nitrate-N, there are options to work with the feed. If testing green chopped or fresh forage, consider fermenting the forage through balage or haylage, understanding that fermentation will lessen the nitrate-N level through microbial activity and growth during the ensiling process. Green-chop and fresh forage will also release the nitrate-N more slowly than dry hay forage. Consider adding the forage to the diet in slow and incremental fashion, while paying close attention to animal health and test the forage as close to the time of feeding as reasonably possible. Ultimately, work with your nutritionist to determine how to best utilize nitrate-N contaminated forage.

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