Livestock producers who rely on purchased feed have an opportunity in this drought to purchase standing dry corn fodder (field corn, sweet corn) to offset potential shortages in hay availability due to waning pasture production. Due to the variability in precipitation during silking, many areas in NJ have fields that have acres of good corn, so-so corn, and some really poor field corn as far as ear development. The stover value of these areas is worth considering as an alternative feed source.

Here is a checklist of questions to ask and sellers to answer to ensure the fodder purchased is fit for livestock consumption and priced accordingly.

Nutritional value of standing corn fodder. With the ear intact, the nutrition value of standing mature corn fodder will be less than 11% crude protein. Cattle need a feed intake of at least 7% crude protein content for their rumen to digest high fiber forages.If the entire crop is harvested and fed, a well-eared corn crop should meet this minimal requirement.

What is an acres worth of standing corn fodder yielding? An acres worth of six-foot-tall well populated standing bone-dry corn fodder can yield at least five tons of chopped corn fodder. The taller the corn and the higher the population, dry fodder yields can exceed 15 tons per acre. This is the same as saying exceptional silage corn harvested at 65% moisture will yield up to 30 ton per acre. Many fields of early planted longer day corn exceed seven feet in height. There is a ton of potential fodder out there if one can obtain it.

Doing the math. On average, NJ producers are purchasing hay to get them through 5 to 8 months until the next grazing season. With the drought, this is looking like 285 days’ worth of stockpiled feed is in order. At 35lbs/ DM intake a day, an acres worth of chopped corn fodder at 5 tons per acre (10,000 lbs.) can feed one cow for 285 days. An exceptional field (30,000 lbs.) can provide fodder for three cows for the same time period. In this scenario we are either grazing combined residue or chopping standing corn and feeding daily (grazing; or windrowed, chopped, or baled).

Current prices of standing corn with ear intact. Locally, hay yields have been impacted by the lack of rain, driving up prices. In South-Jersey, the bushel value of a well-eared corn crop in grazing value is at least $600.00 an acre. This value is comparable to the current market price of $300/ton premium alfalfa or alfalfa-grass (two ton per acre in yield) equivalency. Remember, with the ear, comes the energy that is lacking in hay rations alone.

Grains (corn, wheat, barley, oats) contain on average about 80% total digestible nutrients compared to just 42% in low quality to 58% TDN in high quality hay. To put that into perspective, if a 50 lb. bag of 17% minimum CP fitting ration containing 18% maximum fiber is costing $10.00/bag, its value is $400/ton and doesn’t come with 35 lbs. of fiber. The value of the corn still in the field is 7% CP; is 30% higher in energy; and has the additional value of the bulk of the daily fiber intake that drives cow rumination.

Cover crop planting deadline may incentivize dry fodder chopping. If soil moisture conditions remain poor, sellers may be incentivized to get rid of the biomass so they can plant winter wheat and barley in October to ensure a good stand establishment. Without soil moisture and adequate rainfall, traited corn stalk residue can take more than a year to break down. In high biomass fields (>6 foot tall), the amount of residue remaining impedes planting and emergence in no-till.

Value after combining. Without kernels, corn fodder with some leaves intact after combining can provide only about 5% crude protein but the cob, leaves and stalks are still providing more than 50% TDN. The equivalent value of combined corn fodder is equal to or slightly better than good wheat straw. But very poor-quality wheat straw may only have 22% TDN. Current regional market prices suggest post-combined corn fodder value (cob, leaves, stalk but no kernals) in NJ is worth $200-$300/acre if yielding one to two tons per acre. Or 33% to 50% of the bushel value of the crop per acre if yielding 100 bushels/per acre.

Value of low nitrates. April and May planted corn is the least likely to have high nitrates based on past precipitation patterns. These fields are ideally the ones to consider purchasing to graze or harvest as dry corn fodder and should fetch a premium if optioned to be harvested as corn fodder.

June and July planted corn has to be tested for nitrate levels. If no nitrogen other than starter was applied and no chicken manure was applied, early planted corn is least likely to have high nitrates. Any other scenario requires a nitrate test of the stalk and leaves. Nitrates and prussic acid accumulate in drought stressed crops that received nitrogen fertilizer or high amounts of high nitrogen containing manure and can kill livestock. In a year like this, do not feed recently frosted corn that was not already mature or dead (leaves brown and ear hanging) without first testing for nitrates if fertilizer or manure was applied during the growing season.

For more important information on the risks of drought induced nitrate poisoning, see https://plant-pest-advisory.rutgers.edu/feeding-nitrate-containing-forages/

Weed presence must be factored into decision. Fields with johnsongrass and shattercane are not only a risk for nitrate and prussic acid poisoning during a drought, but the weed seeds will pass through the manure. Before choosing to purchase a corn field for fodder, walk the field. Jimsonweed is also toxic in large quantities. Heavy infestations of pigweeds and common lambsquarters can also result in nitrate toxicity. Before grazing, determine the date of the last herbicide application and review the grazing and slaughter withdrawal language in the label for each product, as many broadleaf herbicides have 7 days to 8 weeks feeding restrictions since application. For a quick look, see the USDA fact sheet Appendix H. Grazing Restrictions by Herbicide.

Additional resources:

2021. Progressive Forage article by Melissa Bravo. Adverse weather impacts essential nutrient uptake
2022. Penn State Extension fact sheet on corn fodder

2019. Hay and Forage Grower article by Melissa Bravo. Quality corn stover in high demand