DSynergy: Evaluation of Stocking Rates and Strip-Grazing Management of Cows Grazing Corn Residue with Distillers Grains Supplementation

Justification

Ethanol production continues to grow at a record pace. The high demand for corn to be used in ethanol production has resulted in high corn prices. More land is being taken out of hay production and going into corn production. The end result is that feed prices are all considerably higher than past years. Producers are now looking for inexpensive alternatives to hay and other stored feeds. One alternative in Illinois we do have is an abundant source of corn residue to graze. Corn residue does not have an adequate supply of protein or phosphorous for cattle. Also, energy may be limiting depending on the condition of the cows and targeted weight gain. With the increased ethanol production, there is also an increase in distillers grains (DDGS). DDGS are high in protein, high in phosphorous, and have an energy value of approximately 120% of corn. DDGS are high in digestible fiber and have very little starch and thus should not depress fiber digestion. This makes an excellent supplement to grazing corn residue. Corn residue and distillers grains are readily available to Illinois producers and could provide for 2 to 3 months of inexpensive feed in the fall after calves are weaned. As ethanol production continues to grow and the demand for Illinois corn to be used for fuel production increases, beef producers will be looking for a feed replacement. This system would allow for corn to be utilized for fuel production while the ethanol co-product (DDGS) and the corn crop residue would be utilized for cattle feed.

Objectives

  1. Maximize production per acre by harvesting corn grain and utilizing DDGS and corn residue for cattle
  2. Compare stocking rates of 1 and 1.5 cows per acre
  3. Compare strip grazing management with moving fence either every week or every other week
  4. Determine costs of each system

Treatments (All cows fed 4 lbs of DDGS)

1 cow / acre (fence moved every 2 weeks)
1.5 cows / acre (fence moved every 2 weeks)
1.5 cows / acre (fence moved every week)

Procedures

192 spring-calving gestating cows were utilized to determine the effect of strip-grazing management of corn residue with DDGS supplementation on cow performance. There were two replications of each treatment: 1 cow / acre (fence moved every 2 weeks), 1.5 cows / acre (fence moved every 2 weeks), and 1.5 cows / acre (fence moved every week). Each of the 6 corn residue fields were 24 acres. 24 cows were in each of the 1 cow / acre groups and 36 cows were in each of the 1.5 cows / acre groups. The fields where the fence was moved every two weeks were divided into 3 equal sections and the fields where the fence was moved every week were divided into 6 equal sections. Cows grazed for 42 days. All cows were fed 4 pounds of DDGS on the ground each day. Cows were weighed and assigned a body condition score (BCS, scale of 1-9) at the beginning and end of the grazing period. Body weight (BW) change, BCS change and cost of grazing were calculated for each group.

Results

Cow performance data are presented in table 1. There were no statistical differences in BW or BCS. All cows did gain BW and BCS with the cows that were stocked at 1 cow / acre having numerically the highest BW gain. Economics are shown in table 2. The two heavier stocking rates resulted in a lower cost/ hd/ day than the lower stocking rate. There was no difference in cost per day between the fence moved every week and every 2 weeks treatments.

Table 1. Effects of strip-grazing management on cow performance
 

Treatments

Item

1 cow /acre (2 wk)

1.5 cows/ acre (2 wk)

1.5 cows/ acre (1 wk)

Initial BW, lbs

1260

1276

1272

Final BW, lbs

1343

1340

1318

BW Change, lbs

83

63

46

Initial BCS

5.4

5.4

5.3

Final BCS

5.8

5.7

5.8

BCS Change

0.4

0.3

0.4

 

Table 1. Effects of strip-grazing management on cow economics
 

Treatments

Item

1 / acre (2 wk)

1.5 / acre (2 wk)

1.5 / acre (1 wk)

Corn stalks ($10/acre), $/hd/d

$0.24

$0.16

$0.16

DDGS ($100/ ton @ 4 lbs/hd/d)

$0.20

$0.20

$0.20

DDGS feeding labora , $/hd/d
(1.5 hrs for all 192 hd)

$0.09

$0.09

$0.09

Fence moving labora , $/hd/d
(20 minutes – 2x or 5x)

$0.01

$0.01

$0.02

Total cost, $/hd/d

$0.54

$0.46

$0.47

a Labor @ $12/hr

Conclusions

All cattle gained body weight and body condition. Stocking cows at 1.5 cows/ acre resulted in the cheapest cost/day. Weather can have a major impact on residue grazing. A late harvest and wet fall limited the grazing period of this study.

Project Personnel

Daniel W. Shike (Ph.D.), Visiting Assistant Professor, Dept. of Animal Sciences, University of Illinois

Dan B. Faulkner (Ph.D.), Professor, Department of Animal Sciences, University of Illinois

Edward N. Ballard (MS), Retired Animal Systems Educator, University of Illinois

Project Resources