Determine dormant-season forage supply to reduce hay feeding costs
Posted on: Nov 12, 2013
Have you calculated fall forage reserves? If not, you may incur unnecessary hay feeding costs.
On a recent tour of a Colorado ranch, we helped the rancher calculate forage reserves in a variety of pastures for a herd of 1200 mother cows. This rancher needed to determine how much additional hay he needed to buy as a supplement for dormant-season forage. He had built the genetic base of his herd, so did not want to sell animals if his forage supply ran short. He chose to purchase hay, but didn't know how much he needed to buy.
We traveled each pasture his cows would enter during the dormant season and calculated forage reserves across each pasture. When running the numbers, we determined he had enough forage to make it through the winter without having to feed additional hay. He had originally budgeted $100,000 for hay purchase, but forage calculations revealed he wouldn't need to use that money. This represented a huge cost savings for his operation, and a major stress relief for him as well.
This example illustrates how simple and quick forage calculations can save livestock producers a great deal of money when considering hay purchases. Performing these forage surveys in the early stages of the dormant season can be a revealing exercise and a handy planning tool.
Here's how it works:
Ranchers should ensure that their stocking rates correlate with forages supplied in their pastures. The best way to do this is to determine forage availability through simple pasture assessments. See the picture below...
These cowboys have staked out a parcel of land they believe would feed their one cow for one day. They have defined an "animal day," a terrific unit of measure for tracking forage availability. They must next measure the length of a side of this square they have staked so they can determine stocking rate of a pasture in animal days per acre, or ADAs. In this arrangement, an ADA equals the number of square feet in an acre (4840) divided by the length of a side of a square squared.
As an example, assume each side of this square is 30 steps long. If a step is roughly 3 feet in length, then they can calculate their stocking rate by dividing 4840 / 30 / 30 = 5.4 Their calculated stocking rate is therefore 5.4 ADAs.
They use a basic equation to determine how long their herd can remain in a given pasture:
Stocking rate = Number of animals * days per pasture / acreage.
As an example, assume the pasture is 500 acres and the herd size is 200 animals. Then, using that 5.4 ADA stocking rate, they can determine that the grazing duration in their pasture is 13 days (5.4 ADA = 200 head * grazing duration / 500 acres).
Repeat the ADA sampling process a handful of times to increase the precision of stocking rate in each pasture. Then take the ADA average to use as the basis for calculating stocking rate, and therefore the number of days to be spent in a pasture.
This process provides ranchers increased confidence in determining if pasture forage supplies will meet demand by the herd. The technique allows forecasting of forage supplies well in advance so use of costly stored forages (hay) can be minimized.
This example uses a smaller herd that the 1200-head herd described above on the Colorado ranch, but the process is the same regardless of herd size.