Alkaline Treatment Of Low Quality Forages (Corn Stovers) Back »

Ruminant animals allow us to utilize low quality forages that have limited other uses. Researchers are always looking for measures to reduce feed cost by improving low quality forages and increase their nutritional value to the animal in order to reduce the largest expense item in producing beef.

Recently, alkaline treatment as a method to increase the value of low quality roughage has been re-evaluated. The technology is not new, but is worth revisiting due to increased feed costs

One version of alkaline treatment is the quicklime or hydrated lime treatment. How does the lime treatment work? It works by increasing the digestibility of the fiber. The treatment swells the cellulose, which makes it easier for the enzymes to work. Additionally, the hydrogen bonds between lignin and hemicellulose are hydrolyzes.

Feedlot research at Iowa State showed a $28.04 higher return per steer for corn replacement feed (CRF), or Ca(OH)2 treated corn stover, compared to a corn based ration. The steers were fed diets for 183 days (Table 1). Steer performance was similar; however, the CRF-fed steers used 30 bushels less corn.

Table 1. Iowa State Study Diet composition.

Ingredient % DM
Corn Ration
Corn Replacement Feed
Corn grain
70
35
Untreated corn stover
5
0
Ca(OH)2 treated corn stover
0
20
Modified distillers grains
20
40
Supplement
5
5

Steers fed for entire 183 day trial. Adapted from Russell et al. 2011

Shreck et al. (2012) treated wheat straw or corn stover with 5% calcium oxide. Diets were 36% dry rolled corn, 40% wet distillers grain solubles, 4% supplement and 20% either treated or untreated wheat straw or corn stover. The control diet was 46% dry rolled corn, 40% wet distillers grain solubes, 4% supplement and 3.3% of each untreated cobs, straw and stover. Table 2 shows that cattle on treated wheat straw and corn stover diets were fed more roughage and less corn and gained as efficiently as cattle on the control finishing diet. Steers fed treated wheat straw or corn stover had heavier final weights and hot carcass weights, higher ADG and improved F:G compared to untreated wheat straw or corn stovers. Treated residues had greater profit than untreated when corn was priced at $3 to $6.

Table 2. Performance and carcass characteristics from animals fed treated or untreated corn stover and wheat straw.

   
Wheat Straw
Corn Stover
Item
Control
Treated
Untreated
Treated
Untreated
Final BW, lb
1376ab
1414a
1292b
1402a
1373ab
ADG, lb
3.78abc
4.01a
3.55cd
3.83ab
3.49d
DMI, lb
25.81
25.83
25.29
26.11
25.06
F:G
6.83ab
6.44a
7.12b
6.82a
7.18b
HCW
834bc
857a
811cd
841ab
805d
Marbling
517
508
484
501
494
 
Profit - $3.00
0.00
$17.37
-$10.28
-$0.05
-$13.32
Profit - $4.50
0.00
$35.80
-$2.08
$13.68
-$6.70
Profit - $6.00
0.00
$54.16
$6.04
$27.33
-$0.16

Shreck et al. (2012)
abcd Within a row, values lacking common superscripts, differ (P < 0.05)

Depending on the price of corn and crop residues, and the labor, material and equipment costs to treat the roughage, this technique can be a cost effective strategy for feedlots. However, it is less economical to use with growing calves or cows.

Corn stover is chopped to reduce particle size and increase surface area. It is suggested to use a 3 to 6 inch screen. The original research was done by adding 5% calcium oxide, adding 7% calcium hydroxide is safer and easier to handle. This is not limestone, adding limestone would have no effect on fiber digestibility. You need to add enough water to make a 50% dry matter feed. The treated corn stover needs to be stored for 7 days in an airtight system such as an Ag bag or bunker.

Several reasons to select calcium instead of sodium based chemical would be: 1) less environmentally harmful to cropland and future crop production, 2) serves as a source of supplemental calcium, 3) less caustic to equipment. Be sure to follow instructions on label for human safely.

Based on conversion by researchers, the cost of treating corn stover or wheat straw ranges from $20 to $60 per ton. This is doesn’t include the cost of the residue. Before deciding to treat low-quality forage, determine the cost per ton at your operation.

References:

  • Russell, J., D. Loy, J. Anderson, and M. Cecava. 2011. Potential of Chemically Treated Corn Stover and Modified Distiller Grains as a Partial Replacement for Corn Grain in Feedlot Diets. Iowa State University Animal Industry Report 2011. A.S. Leaflet R2586.
  • Shreck, A.L., B.L. Nuttelman, W.A. Griffin, G.E. Erickson, T.J. Klopfenstein, and M.J. Cecava. 2012. Chemical Treatment of Low-quality Forages to Replace Corn in Cattle Finishing Diets. 2012 Nebraska Beef Cattle Report. Pp. 106-107.
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