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.
October 31, 2023
Author: John Goeser, PhD, PAS, Diplomate ACAN
2023 Hay and Haylage Quality Across the US
The 2023 growing season ended up being a contrast to 2022 for many. Dry conditions to start the year contrasted with 2022’s generally desirable growing conditions for Midwestern and Eastern growers. To the West and South, the decade-long drought gave way to snow and rainfall and provided moisture for growers. The resulting impact on the 2023 alfalfa and grass crops for hay or haylage has proven fascinating.
Hay and haylage quality is primarily determined by fiber content, understanding fiber is the least digestible nutrient in forage. The calories in fiber unlocked by dairy or beef cattle are generally half that realized from starch, sugar or protein. With this in mind, crop quality summaries begin with assessing fiber content. For this Data Distillation, crop year can be defined as April 1 through October 1, 2023.
Western Hay
The increase in snow, irrigation, and rainfall equated to greater fiber content in 2023 hay relative to the prior two crop years as highlighted in Figure 1. Often, fiber content and fiber digestibility are negatively correlated, understanding that more mature hay tends to have higher fiber content. Indeed, the total tract NDF digestibility (Figure 2; TTNDFD, % aNDF) decreased for 2023 relative to the prior two crop years. Interpreting these two observations, the hay quality for the West is down substantially for 2023.
Figure 1: Western US hay fiber content (aNDF, % DM) for samples analyzed by Rock River Laboratory since 2021.
Figure 2: Western US hay fiber digestibility (TTNDFD, % aNDF) for samples analyzed by Rock River Laboratory since 2021.
Midwestern Haylage
Contrasting with the Western hay observations, the Midwestern haylage crop was very different, being substantially lower in fiber content compared with the 2021 and 2022 growing season (Figure 3). These observations are attributed to the drier growing conditions and likely greater leaf to stem ratios, understanding leaves are higher in protein than stems. The fiber digestibility was not dramatically different from prior years (Figure 4), however with less fiber growers and producers should expect substantially greater energy value in 2023 haylage.
Figure 3: Midwestern US haylage fiber content (aNDF, % DM) for samples analyzed by Rock River Laboratory since 2021.
Figure 4: Midwestern US haylage fiber digestibility (TTNDFD, % aNDF) for samples analyzed by Rock River Laboratory since 2021.
Eastern Haylage
For the Eastern US growers, the 2023 haylage fiber content was up relative to prior years (Figure 5), however the fiber digestibility was also up (Figure 6). These two observations may be unexpected but could suggest growing conditions positively impacted the fiber digestibility to a greater extent than harvest maturity when evaluated across the crop year. The energy value for Eastern US haylage appears to be average thanks to slightly increased fiber content coupled with greater fiber digestibility.
In summary, the 2023 growing season yielded very different results compared with 2021 or 2022 across three different US regions. There are likely within region and within farm deviations from these summaries, however the growing season clearly continues to have a substantial impact upon forage quality.
Figure 5: Eastern US haylage fiber content (aNDF, % DM) for samples analyzed by Rock River Laboratory since 2021.
Figure 6: Eastern US haylage fiber digestibility (TTNDFD, % aNDF) for samples analyzed by Rock River Laboratory since 2021.
September 5th, 2023
Author: Cliff Ocker
How long should we let corn silage ferment before feeding it?
As nutritionists, we are often asked this exact question every fall. For some, inventories may be running out and they have no choice but to feed new crop corn silage immediately. However, if we can manage our inventories, what are some of the benefits of letting the silage ferment prior to feeding it? And how long should that be?
Knowing that cows like consistency, fermented feed provides a much more consistent forage base for the animals, as compared with fresh feeds. When we feed fresh forages, we need to consider things like nitrate levels and heating/unstable forages. Once fermented, we have a lower pH, a more stable forage in terms of lactic and acetic acids, as well as a forage with much more digestible nutrients.
Good management practices at harvest will help ensure the best outcome from fermentation and a stable and consistent forage. Proper whole plant moisture is key when harvesting corn silage to make sure the forage can be packed appropriately and keep oxygen out for fermentation. This creates a quick drop in pH and allows lactic and acetic acids to cure and stabilize the forage. Proper fermentation will also help keep anti-nutritional factors - like molds, yeasts, and soil-borne pathogens - at bay.
There are many benefits to the fermentation process. First, a quick and efficient fermentation will use or burn up fewer nutrients than an inadequate fermentation. Water soluble carbohydrates (sugars) are some of the first to become bug/bacteria food, and a quick fermentation will utilize less of these nutrients, thus leaving them available for the animal as an energy source. Other nutrients become more available or digestible over time in storage. Ammonia levels also increase, providing more soluble protein. Plus, starch will become more digestible over time.
Figure 1 shows how pH changes over time in one of the previous corn silage crop years. This is reviewing all of the Rock River Laboratory data and assuming that corn silage was all harvested around Sept 1st.
Figure 2 provides a graphic of how lactic acid changes over time.
Figures 3 and 4 show starch digestibility change over time in storage from different crop years. As we know, a number of factors influence grain from year to year.
We like to think that forages are fermented and ready to feed in three weeks and while much of the fermentation process is complete by then, note the potential benefits to further changes over time in storage. Perhaps we should consider managing to let our corn silage crop sit for a couple of months to have the most consistent and most digestible forage for our herds.
August 9th, 2023
Author: Katie Raver, MS, PAS
When assumptions translate to economic deficiencies
When it comes to feed, there are many assumptions that we accept as fact, just based on how long we have been doing so. However, as we dig into feed data and are able to watch feed trends over time, it showcases why assumptions can be detrimental and should be questioned. One common assumption is that moisture changes are indicative of other nutrient changes in feed. So if we don’t see big changes in moisture, we may assume other things aren’t changing. However, we know that this is not always the case. As seen in Figure 1, we may assume due to the relatively stable nature of the moisture content that all other nutrients are also stable.
Figure 1: Corn silage three sample average moisture over time
When we look at the nutritional data from these samples, surprises ensue. Figure 2 showcases starch over the same period of time. When moisture was changing, starch was relatively stable, and at the end of this graph moisture is stable and starch is rapidly changing. These changes in starch, unaccounted for, can lead to unexpected changes in ration nutrient composition and starch load. If not corrected, this oversupply of starch has immense economic value. At 10 pounds of dry matter (DM) intake corn silage per head per day, the additional starch in this example is equivalent to one additional pound of corn or nearly 12 cents.
Figure 2: Corn silage three sample average starch over time
We may also assume that this just applies to forages, however the same is true with commodities. Figure 3 showcases that while this soybean meal (SBM) moisture was relatively consistent over this 6-month period, there was often a 1-1.5-unit swing in crude protein (CP). This may seem like a relatively minor difference, but such changes in CP could easily account for 0.05-0.1 pounds of CP per head per day or around 3 cents per head per day.
Figure 3: Soybean meal three sample average crude protein over time vs. moisture over time
It’s likely tempting to use moisture as a gauge for overall feed changes, but there are countless instances similar to the aforementioned that showcase why this can be very misleading. In times of low margin, such assumptions are costly. Understanding the true and comprehensive feed nutritional value can have a positive benefit on the bottom line in addition to assuring our formulated ration closely matches the fed ration.
May 9th, 2023
Author: John Goeser, PhD, PAS
Corn grain trending harder
Starch digestibility in starch-rich feeds is increasingly recognized to affect dairy and beef performance, feed conversion efficiency, and farm profitability. Dairy and beef nutritionists will readily assess corn silage, high moisture corn, or snaplage starch digestibility using rumen in situ starch digestibility measures, with a 7h rumen incubation period. Commercial feed analysis near-infrared reflectance spectroscopy (NIRS) models have sufficiently evolved to accurately measure starch digestibility as impacted by growing environment, seed genetics, plant nutrient metabolism and health, and fermentation extent.
Each of these factors is known to have an impact on starch digestibility, and in situ rumen starch digestibility NIRS models help farmers benchmark their feeds while making nutrition adjustments to improve profitability. Dry ground corn grain starch digestibility is not affected by fermentation, given none has occurred. However, shelled corn hardness and starch digestibility can be influenced by seed genetics, plant nutrient metabolism and health, and growing environment. NIRS in situ rumen starch digestibility models are also robust for dry ground corn.
Historically, yellow No. 2 corn has been assumed a commodity. Feed library values have driven diet formulation and feed purchasing decisions. Thanks to commercial feed analysis advances and more farmers testing their grain, consistency in commodity corn grain is being questioned. Meaningful deviations in nutrient content and starch digestibility have been uncovered on a case-by-case basis. Now, with thousands of dry corn analyses over the past three crop years to draw insight from, an impactful trend has come to light. The 2021 and 2022 crop years’ dry ground corn is less digestible.
Figures 1 and 2 demonstrate the population distributions for starch content and in situ rumen starch digestibility with dry corn samples analyzed by Rock River Laboratory for the Midwestern and Eastern US regions. Notably, there is slightly less starch content in 2022 and 2021 crop years, relative to 2020 corn. More importantly, though, the corn grain in situ rumen starch digestibility is lagging behind, with 2022 corn around 10 percent less than 2020 corn.
Figure 1: Dry ground corn starch content, % of dry matter, for thousands of samples analyzed by Rock River Laboratory over crop years 2020, 2021, and 2022 for Midwestern and Eastern US.
Figure 2: Dry ground corn in situ rumen starch digestibility, 7h, % of starch, for thousands of samples analyzed by Rock River Laboratory over crop years 2020, 2021, and 2022 for Midwestern and Eastern US.
Do not assume that commercial dry ground corn is a consistent commodity. Rather, consider checking your corn quality and discuss the impact that measured corn grain quality and digestibility have, relative to feed library benchmarks. Corn grain is increasingly valuable, and decreasing corn grain particle size can help offset less digestibility. Future data distillations will discuss corn grain particle size and revisit the relationship with rumen starch digestibility.
April 3rd, 2023
Author: Cliff Ocker
Don't Overlook the Opportunities with Small Grain Silage
As spring has sprung, those with livestock look to planting and harvesting crops for another year. One of the first in the new crop season will be small grain silage. Interestingly, looking at lab data, this crop tends to be quite variable in terms of quality. Several reasons exist for that but consider ahead of time what your goal is for this feedstuff and maximize the harvesting opportunity.
Small grains can be planted as a cover crop, double-cropped for extra forage for dairy or beef, or to let go to harvest the grain. Whatever the plans for this crop, it is best to know ahead of time what quality of feed is sought as this crop can change quite rapidly. Likely, the biggest influencer of quality for small grain silage is maturity. If seeking more tonnage vs a high-quality dairy forage, the timing to make it may be different.
Looking at crop year data over the past three years, similar quality swings within crop years can be seen. Figure 1 shows Total Tract NDFD (TTNDFD) for small grain silages. TTNDFD is a calculated value based on four different NDF Digestibility time points and does a better job quantifying fiber digestibility than, say, Relative Feed Quality (RFQ). The average TTNDFD of small grain silage is running in the low to mid 40’s with the lower quality samples 10 points below the average, while the best quality is 10 points above. Again, depending on the goals for the forage, this can have huge implications for livestock.
Figure 1: TTNDFD of Small Grain Silages
| Crop Year | p15 | Mean | p85 | StDev |
|---|---|---|---|---|
| 2020 | 35.98 | 44.39 | 53.85 | 7.97 |
| 2021 | 33.756 | 43.73 | 53.73 | 8.72 |
| 2022 | 34.49 | 43.09 | 52.00 | 7.88 |
Once the crop’s goal has been determined, keep an eye out for maturity, then look for a window (in the weather) to harvest the forage. Harvesting at the correct moisture is another key factor that influences not only the forage quality, but also fermentation and shelf-life. Depending on the storage type, typically a DM of between 30 and 40 percent works best. Less than 30 percent DM will typically create runoff or loss of nutrients, while over 40 percent DM can create packing challenges on this softer crop.
Putting up a clean feed is another component of high-quality forage. Soil contamination can be a major challenge when harvesting this crop since it’s cut so close to the ground. Natural ash levels in small grain silage typically run between 7 and 9 percent. Note in Figure 2 that the best (15th Percentile) ash levels are at 9 percent ash, with an average of 11 percent and many samples running above 14 percent. Ash acts as a buffer in the fermentation process, elongating fermentation and slowing the pH drop. A less-than-ideal fermentation allows molds and yeast to grow and multiply while feeding on the very nutrients that were meant for livestock consumption.
Figure 2: Ash Content Levels of Small Grain Silages
| Crop Year | p15 | Mean | p85 | StDev |
|---|---|---|---|---|
| 2020 | 9.05 | 11.37 | 13.78 | 2.35 |
| 2021 | 9.14 | 11.64 | 14.17 | 2.49 |
| 2022 | 9.26 | 11.92 | 14.59 | 2.58 |
Small grain silage can be a great crop to feed alongside or help stretch other forages further in the ration. Decide what quality of forage you would like and work to hit the correct maturity at harvest, harvest rapidly, and with as little soil contamination as possible. Hitting the correct moisture will help get an appropriate pack (density) and provide a better fermentation that produces high-quality forage for the best performance of your livestock.