2022 Corn Silage Summary
The majority of corn silage (CS) harvest took place in September or October of 2022 (may have been earlier in the SE) and has shown great variability across the US, due to differences from wet to drought stress growing conditions. Compared to 2021, there were less growing degree days (GDD) for many areas and tremendous variations in rainfall. It was a cold and wet spring, which delayed planting in most areas.
Corn silage is typically included at higher levels in a lactating cow diet. It can contribute significant amounts of digestible fiber, starch, and peNDF, as well as protein and fat. Most variability is observed in the fiber and starch levels and digestibility, which impacts dry matter intake, milk yield, and components. Corn silage data compiled from Rock River Laboratory for the West (W), Midwest (MW), and East (E) US regions is summarized below.
Corn silage in the E is slightly drier (~37%DM) than previous years with strong GDD and advanced crop maturity. Starch is higher than previous years (~38 % DM). A higher grain to stover ratio means slightly less fiber and more starch but total fiber digestibility is about the same as last year. 30-hourneutral detergent fiber digestibility (NDFd30) is more variable but was higher than last year. Lignin anduNDF240 as % DM are lower compared to 2021 partially due to a higher grain ratio. This year’s drier silage with potentially harder kernels may cause challenging rumen starch digestibility (starchd), however, this should improve with longer time in storage.
The MW CS average DM is closer to 35% with the average starch over 35% DM, up from last year. NDFd30 is moderate but uNDF240 is higher due to greater plant lignification. Total digestible fiber (TTNDFd) is better this year compared to the last 3 years. Similar to the E, mature and hard grain may challenge rumen starchd.
Corn in the W may have experienced drought conditions. Corn silage has good DM (~35%) but lower average starch levels (~30% DM) this year. Fiber digestibility (NDFd30) is lower while uNDFd240 and lignin are higher compared to previous years. Total NDF and starch are estimated to be faster digesting for this year’s silage. Corn silage ash content (~6 % DM) continues to increase year over year. Ash content in CS may be greater because it was a dry year last year and irrigation splashed more dirt on plants, many piles are on dirt and the packing equipment has more dust on tires each turn, and there are more irrigation circles with pumping water vs gravity irrigation. In terms of CS Kernel Processing Score (KPS) the Western US is taking the lead. The new KPS goal is 75 to 80.
In Ohio and Indiana, there have been reports of Vomitoxin (DON) and Zearalenone (ZEA) in corn grain. It seems to be highly variable between areas. According to Dairyland Labs, 2022 CS seems to have higher concentrations of DON and ZEA. Yet, keep in mind samples submitted for mycotoxin analysis are ones already suspected of toxins and sampling is not random. Table 1. DONCS summary from 2020-2022 reports a gradual increase in DON throughout the years, with a greater jump in positive samples> 2.5 ppm DON.A similar increased trend for ZEA in CS throughout the years but not as prevalent as DON (Table 2). Dairyland reports no significant changes in T2/HT2 and Fumonisins (FUM) compared to previous years. However, 6% of samples are over 5ppmfumonisin for the SW US. 2.5% of analyzed CS samples were positive for Aflatoxins (AFL) and 2.3% were positive for Ochratoxin-A. Also keep in mind that corn grain with high mycotoxin levels might be used for ethanol production. Mycotoxin levels will be elevated in distillers produced from contaminated corn.
Complied CSA data of the new crop (2022) mycotoxin are shown below (Table 3). Corn grain samples from IN had the highest DON (19 ppm) and ZEA (1,000ppb) levels. Corn from NC, KY, and MO was detected with the highest FUM levels (>5 ppm). DDGS samples were 100%positive for DON, ZEA, and FUM, while 62% positive for AFL. Samples were tested at CSA Labs using a lateral flow test.
➢For more information on mycotoxin testing, ask your Nobis Agri Science Nutritionist
New York and Vermont Corn Silage Hybrid Evaluation Program
Cornell University, University of Vermont, and seed companies collaborate to evaluate different CS hybrids. Hybrids were either entered into the 80-95 day relative maturity (RM) group (Early-Mid) and were tested at two locations in NY (Lamb Farms in Oakfield and the Willsboro Research Farm in Willsboro) and one location in VT (Border view Farm in Alburgh) or were entered into the 96-110 day Table 3. CSA 2022 Data; Number of Positive Mycotoxin Samples by Ingredient Table 1. Dairyland Labs DONCS Summary, 2020 to 2022. Table 2. Dairyland Labs ZEACS Summary, 2020 to 2022. January 2023 relative maturity group (Mid-Late) and were tested at two locations in NY (Greenwood Farms in Madrid and the Musgrave Research Farm in Aurora) and one location in VT (Border view Farm in Alburgh).
Similar to the rest of the US, the NE growing season varied greatly from the drought conditions in Western NY, excessive early season moisture in St. Lawrence County, and a generally wet season from start to finish at the Alburgh, VT location. These differences were captured in the field locations in the NY VT Corn Silage Hybrid Evaluation Program published by Cornell University.
These results will help producers in the NE understand what to expect when transitioning to 2022 CS compared to prior years. The location-to-location weather inconsistency in 2022 increases the importance of concentrating on location specific data where weather patterns were most comparable to your farm’s location. Although fresh samples are a helpful indictor it’s important to remember that forage characteristics will change with time in storage e.g., starch digestibility.
Growing degree day accumulation did not standout in either direction for 2022, although it was noted that harvest timing at the Willsboro and Aurora NY locations resulted in a lower than desired whole plant DM. Overall for the NY and VTCS samples ,the highest percentage of samples have a uNDF240 of11 to 12% DM and nearly 50% of samples have a starch content of 38% or greater. However, it is recommended to look at location specific data for a better understanding of how 2022 CS is affected by a specific growing environment. It is suggested that 2022 CSuNDFd240 will support feeding programs similar to 2021 CS. Since two of the locations were harvested earlier than preferred, this may affect starch content, as generally starch content tracks closely with whole plant DM. There may have been opportunity for starch content to be greater than what was reported if the plant was harvested in the target range of around 35% DM.
In summary, each year brings its own challenges and opportunities. There is a wide range of CS quality across the US this year (likely true for most years). Starchd is slow and falling behind for a great deal of the US. Fecal starch samples may be beneficial to find starch and grain feeding opportunities. Weather during the growing season has impacted nutrient content in certain areas; I t is important to test your own forages to better understand site specific impacts of the growing season. It is advisable to test silage for mycotoxins if suspected as they are highly variable across the US.
CSA Animal Nutrition, 2022 Crop Summary W, MW & E US Regions. 2022. Dr. John Goeser, Rock River Laboratory, Inc. Powerpoint. New York and Vermont Corn Silage Hybrid Evaluation Program. Dec. 2022. Lawrence, Joseph et al., Cornell University Department of Animal Science.