Harvesting and Feeding Corn Stalks

Neither plastic net wrap nor biodegradable twine get digested by rumen microbes.
( Troy Walz, University of Nebraska )

The person who originated the adage, “It beats a snowbank” may have been thinking about feeding corn stalk bales. However, like most forages there can be quite a bit of variability in nutritional value.

Over the past several years we have submitted over 40 different samples of corn stalk bales through our office. Usually the bales fall into two different ranges. Those that are lower quality are usually between five and six percent crude protein and around 48 percent total digestible nutrients (TDN) on a dry matter basis. Those which test with more feed value are about seven percent crude protein with a TDN somewhere around 52 percent on a dry matter basis. The primary difference between those of “lower” and “higher” quality seems to be the harvest method. Those stalks which were harvested directly behind the combine and not shredded are usually of higher quality than those that were mowed,  raked and baled.

By far, the best method to utilize corn stalks is to harvest them with four legged harvesting machines (cows).  In addition to using less labor and being less expensive, cattle will only harvest the highest quality parts of the plant (leaves, husks, grain) and leave the lower quality stalk in the field. This is especially vital in drought years since there is significantly less risk of cattle consuming toxic levels of nitrate because the highest concentration of nitrate in the corn plant is contained in the lower stalk.  Unfortunately, a lack of fencing, water and in some cases, the need to plant a subsequent crop limits grazing of corn stalks. 

On average, stalks baled after corn harvest contain about 6 percent protein and 50 percent total digestible nutrients which is below the protein and energy level required to winter a beef cow as illustrated in the following table.

Nutrient requirements of 1,300 pound beef cow with average milking ability

Stage of Production

Crude Protein %

Crude Protein #

TDN %

TDN Pounds

Mid Gestation

6.9

1.5

49

10.8

Late Gestation

7.7

1.8

53

12.5

Early Lactation

9.1

2.2

55

13.4

The small amount of money spent on a forage test can be valuable when feeding any forage. It is a valuable investment. Not only can you find out the nutrient value, you can also test for nitrate levels, which could be a problem in some fields this year.

 
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