Cows in the corn!

Remember those cows in the corn at the Neely-Kinyon Farm field day last summer?  Here’s the rest of the story.

Twelve cows that had just weaned their first calves started grazing approximately 2 acres of standing corn, which was in the dough stage, on August 17^th.  Electric fencing was used to limit the amount of corn available for grazing on any given day.  The fence was moved every 2 or 3 days to give access to fresh corn.  The corn plot was grazed until October 10^th.  No supplementary feed was fed during the grazing trial.

Weights and body condition scores were collected on August 17, September 15 and October 10.  Two additional animals grazed with the twelve during part of the trial; one from August 17 to September 15, and one from September 15 to October 10.

The corn plot produced 702 cow-days of grazing and bodyweight gains totaling 1340 pounds.  Although the gains per animal were quite variable, ranging from only 2 pounds to 182 pounds, all of the cows had positive gains and improved body condition scores.  Daily gains averaged 1.91 pounds.

Is this cheap feed?  It’s not as cheap as corn residue grazing where all the corn production costs are charged to the corn enterprise, but it’s still reasonable.  Crop enterprise budgets for 1999 developed by Iowa State University economists show pre-harvest variable production costs of $121 and $137 for an acre of corn following soybeans and corn, respectively.  In this trial, an acre of corn produced 351 cow-days of grazing.  Charging the cow $0.35 to $0.40 per day covers the variable costs of producing the corn.

Harvesting the corn by grazing also offers these “fringe benefits”:

• Eliminates harvesting, drying, storage and transportation costs associated with marketing the grain,
• Leaves almost all the nutrients in the field,
• Provides abundant pasture in mid- to late-summer when pastures in Iowa normally make little growth,
• And, in the case of the Neely-Kinyon Farm, the vigorously-growing corn crop provided smothering competition to a remarkable Canada thistle patch.

Russ BreDahl, Extension livestock field specialist

The individual cow data for the “cows in the corn” project follows.