Buckeye Dairy News: Volume 13 Issue 4

  1. Pricing Drought-Stressed and Immature Corn for Silage

    Dr. Bill Weiss, Mrs. Dianne Shoemaker, and Dr. Normand St-Pierre, Extension Dairy Specialists, The Ohio State University

    Because of growing conditions this year, some corn silage will be made from either drought-stressed corn plants or immature corn plants (or both).  Corn silage from either of these types of plants can be an acceptable feed for dairy cows, but they are usually worth less than normal corn silage. 

    Immature Corn Silage – Nutrient content

    The nutrient composition of immature corn silage differs substantially from normal corn silage because the plant contains much less corn grain.  As corn plants mature, concentrations of starch increase (because of increased grain) and this dilutes the fiber (measured as neutral detergent fiber, NDF) and crude protein (CP) concentrations.  The fiber is also less mature which means it is more digestible than in normal corn silage, but the fiber is still less digestible than starch so energy (as measured by net energy for lactation, NEL) is typically lower in immature corn silage than normal corn silage. 

    Average nutrient composition (dry basis) of immature corn silage (very early milk stage)

    CP   10 to 11%                     (about 2 or 3 units higher than normal)
    NDF 50 to 55%                    (about 10 units higher than normal)
    Starch 15 to 20%                  (about 15 units lower than normal)
    NEL, 0.60 to 0.63 Mcal/lb    (90 to 95% of normal)

    As the corn silage crop matures, composition approaches normal.   For Ohio, normal corn silage averages 8% CP, 42% NDF, 30% starch, and 0.66 Mcal/lb NEL.

    Immature Corn Silage – Dry matter concentration

    The greatest potential problem with immature corn silage is its moisture concentration.  Often, dry matter percentage of the standing crop is 20 to 25%, which is too low for a good fermentation.  A nutritious crop WILL BE RUINED by a poor fermentation.  If corn plants are immature, delay harvest until it reaches proper dry matter (~30% for bunkers, ~35% for bags and top unloading silos, and ~38% for bottom unloading silos).  If the corn is extremely late in the season, you may have to harvest after a frost to obtain proper dry matter concentrations.  Frosted corn dries very quickly, so monitor dry matter concentrations often after a frost. 

    Immature Corn Silage - Other issues

    1. Kernel processing can actually reduce the energy value of immature corn silage, and      because the kernel is poorly developed, processing is not needed. 
    2. Frosted corn silage should benefit from the use of a lactic acid bacteria inoculant because the normal bacterial population on the corn may be low.

    Immature Corn Silage – Valuation

    Based on the average nutrient composition shown above and using 3 month average nutrient prices generated with SESAMETM1, immature corn silage is worth about 95% as much as normal corn silage.  However, because of increased risk associated with immature corn silage (composition could vary greatly from the averages), it should be discounted an additional amount.  That amount is difficult to quantify and should be negotiated between buyer and seller, but an additional 5 to 10% discount is probably realistic.

    Drought-Stressed Corn Silage – Nutrient content

    The composition of drought-stressed corn silage does not follow a consistent pattern such as we see with immature corn silage because drought affects corn plants differently depending on when the drought stress occurs.  Therefore, the nutrient composition of drought-stressed corn silage is more variable.

    Average nutrient composition of drought-stressed corn silage (extremely variable depending on drought severity, timing of drought, etc.):

    CP: Usually higher but highly variable, average is about 10% higher than normal or an actual concentration of 8.8%.

    NDF: Usually 5 to 10 units higher than normal (47 to 52%).  Fiber digestibility is probably equal to or higher than regular corn silage.

    Starch can range from very low (~5%) to 25% (only about 10% units lower than normal), depending on kernel development.  If starch is very low, sugars are usually higher than normal.  If diets are formulated for starch, additional corn grain will be needed in diets with drought-stressed corn silage.

    NEL: Limited data are available, but the best guess is 90% of normal (0.60 Mcal/lb).

    Drought-Stressed Corn Silage – Dry matter concentration

    In most cases, drought-stressed corn silage will ferment properly if harvested at the correct dry matter concentration.  However, dry matter concentrations are more variable within a field (or fields) with drought-stressed corn than with normal corn.  This increases the risk of a poor fermentation.  As with immature corn silage, drought-stressed corn silage must be made at the correct dry matter; otherwise, it has much less or no value as a feed.

    Drought-Stressed Corn Silage - Other issues

    1. Drought-stressed corn silage could be high in nitrates which could, if severe enough, make the silage virtually worthless.  All drought-stressed corn silage should be tested for nitrates prior to feeding.
    2. Yields are lower for drought-stressed corn silage; therefore, harvesting costs per ton are increased. This means that the cost of the corn plants should be discounted to cover the increased harvesting cost.

    Drought-Stressed Corn Silage - Valuation

    The nutrient value of drought-stressed corn silage is less than normal corn silage, but without a laboratory analysis of the specific forage, the amount of discount to apply is difficult to determine.  A reasonable estimate is that drought-stressed corn silage has a nutritional value of 90 to 95% of normal corn silage. 

    The relative economic value of the nutrients in drought-stressed corn silage was calculated by using average composition data (8.8% CP, 50% NDF, and 0.59 Mcal/lb NEL) and 3 month average nutrient prices from SESAMETM.  Using that approach, “average” drought-stressed corn for silage is worth 93% as much as normal corn silage.  However, with drought-stressed corn silage, the buyer is taking on substantial risk (highly variable nutrient composition, nitrates, etc.), and drought-stressed corn silage must be discounted to cover this increased risk.  A discount of at least an additional 10% is probably warranted.

    Basics of Pricing Corn Silage

    This article addresses adjustments to be made to silage pricing to account for differences in nutrient content, harvesting, ensiling, and other risks and issues associated with immature and drought-stressed corn silage.  Additional basic corn silage pricing resources are available at https://dairy.osu.edu in issues of the Buckeye Dairy News and under the “Feeding Management” and “Business Resources” links.


    It is absolutely critical that immature or drought-stressed corn silage be made at the correct dry matter.  The value of these silages must still be discounted because of increased risks, including variation of nutrient concentrations, harvest challenges, harvest costs, nitrates, fermentation issues, etc.  Valuing immature corn silage at 85 to 90% of normal corn silage and drought stressed corn silage at 80 to 85% of normal corn silage would be reasonable.  Test drought-stressed corn silage for nitrate levels before feeding.

    1SESAME™ is a software program developed at The Ohio State University to price the important nutrients in dairy rations to estimate break-even prices of all major commodities traded in Ohio and to identify feedstuffs that currently are significantly underpriced. 

  2. Pricing Standing Corn for Silage Harvest - 2011

    Mrs. Dianne Shoemaker, Dr. Bill Weiss, and Dr. Normand St-Pierre, Extension Dairy Specialists, The Ohio State University

    How to price corn for silage as a crop standing in the field is a perennially challenging question.  The optimal answer will vary depending on your point of view.  Are you buying or are you selling? 

    This corn silage pricing discussion is based on a corn crop standing in the field.  The owner’s goal is to recover the cost of producing and harvesting the crop plus a profit margin.  Their base price would be the price they could receive for the crop from the grain market less harvesting/drying/storage costs.  Hopefully, this would meet their goal of covering production costs and generating a profit.  During price negotiations, it should also be recognized that harvest risk is also being shifted from the grower to the buyer.

    To the grain farmer, the corn crop may have some value beyond the income from the sale of grain.  If the crop is sold as silage, the corn fodder is no longer available as ground cover and/or as a source of some nutrients and organic matter.  This creates a potential opportunity for the dairy farm to provide nutrients and organic matter back to the corn fields from subsequent manure nutrient applications.

    Valuing the standing crop
    To look at the value of the corn as silage, we can estimate that a ton of corn silage, on average, contains ~7 bushels of corn.  If corn is worth $6 per bushel, then the standing corn for silage would be worth about $42 per ton before the cost of harvesting for grain. If we estimate a grain harvest (combining, hauling, storing and some drying) cost of ~$40 per acre, then the corn silage is valued at $39 and $40 per ton (depending on yield).  This year, corn prices are highly variable.  Estimating the same $40 per acre harvesting costs, standing corn for silage would be worth $32 to $33 per ton, if corn is worth $5 per bushel; $46 to $47 per ton if corn is worth $7 per bushel; and $53 to $54 per ton if corn is worth $8 per bushel.  This is a starting point, additional adjustments must be made.

    Adjusting for dry matter

    The values discussed above are for corn silage at 35% dry matter.  Prices also have to be adjusted for different dry matter concentrations.  If actual dry matter was 30%, then the value is about $34/ton (i.e., 30/35 = 0.85 x $40/ton). Corn chopped at more than about 38% DM or less than about 30% DM may not ferment properly and can be a problem.  The price for this corn silage should be discounted.

    Considering feed value

    At the 2009 Tri-State Dairy Nutrition Conference, Normand St-Pierre reviewed the difference between valuing corn silage using the 7 bushels of corn per ton method plus harvest and storage costs and an adjustment for 10% fermentation loss, versus pricing based on the prevailing feed nutrient value (Sesame) pricing method (See http://tristatedairy.osu.edu/Proceedings%202009/St-Pierre%20paper.pdf). This method values the silage at what its nutrients are worth based on a wider selection of feed prices plus the harvest and storage adjustments.  The ratio of the two methods for 2005 to 2008, was 1.27.  In other words, the nutrient value of silage to the cow was potentially worth up to 27% more than the value based on the market price for corn.  However, in this particular crop/price year (2011), that ratio is slightly higher at 1.3 to 1.35.

    The SESAME value for Ohio corn silage is available in the most current edition of the Buckeye Dairy News available online at https://dairy.osu.edu.   Remember that this is the nutrient value for AVERAGE corn silage delivered to the cow, so harvest, storage, moisture, shrink and risk costs must be deducted from the SESAME value.

    Other price adjustments and considerations

    So, what does this mean in the real world?  The 7-bushel method is a good starting point.  There could be additional feed value to the buyer which has to be balanced against the harvest and fermentation risks that the buyer is assuming.
    The last factor affecting the value of standing corn is risk.  A farmer purchasing standing corn is assuming risk (Will it ferment properly? Can it be harvested at exactly the right time? What will the final nutrient content be?, etc.). 

    The price for the standing crop should be discounted to recognize these risks.  What is the right amount to discount?  This is not an easy question and is one of the factors to consider when the buyer and seller are negotiating a final price.  Setting the final, fair price for corn silage rests on an understanding of the needs of both the buyer and the seller and negotiating a price that ensures a reasonable profit for both.

    Finally, it is critical that both parties agree on price, payment method and timing, crop measurement, restrictions, and similar details before the crop is harvested!  Ideally, the agreement should be in writing and signed by both parties.  These agreements are especially important when large quantities of crops (and money!) are involved.  While this type of contracting may be uncomfortable for some producers, mainly because they aren’t used to conducting business on more than a handshake, it forces the parties to discuss issues up front and can minimize troubling misunderstandings after harvest.