For many dairy producers feeding a cost-effective ration tops the management worry list. Feed prices and weather, to inventory management and ration formulation – it’s a constant concern with situations and information changing daily.

As a result of these ongoing concerns, the way cows are fed has changed over the years, says Margaret Winsryg, a technical support specialist with Calibrate Technologies. These adjustments were made in an effort to reduce costs; but still ration cost per head per day is higher than any time in the past. Winsryg points out that 10 years ago the average ration cost was $5.50 per cow, today it is $7 to $9.50 per cow, with less grain fed.

“It’s easy to understand that feed prices are variable. What’s not so easy to understand is the variation in how the feedstuff consumed by the cow is utilized by the microbes in the rumen – specifically the amount of starch available to be consumed,” Winsryg says. It’s focusing on this variability that can potentially help dairy producers to be more efficient.

Rumen degradable starch measures how much starch is actually available to the rumen microbes when the feedstuff or ration is fed. Calibrate Technologies has been working on understanding rumen degradable starch for more than 10 years.

Using a precise laboratory test, Calibrate Technologies measures rumen degradable starch on a proprietary GPN indexed scale from one to 11. A GPN score of one equals slow digesting starch (less available to the rumen microbes) and a GPN score of 11 indicates a fast digesting starch (more available to the rumen microbes).

To see the impact of understanding a feed ingredient’s GPN score, Winsryg shares an example of a herd that she works with. This herd was feeding 54 pounds of corn silage at 28 percent starch and a 7.5 GPN. The herd started testing rumen degradable starch levels every two weeks. A month into testing, corn silage tested at 34 percent starch and 8.2 GPN.

Once this herd knew that its starch levels had changed, the nutritionist used this information to adjust the ration, reducing the amount of corn silage fed by 2 pounds.

“While this isn’t a large change and there are many factors that impact profits, it had a huge financial implication for this operation,” says Winsryg. “For example, on a 1,000-cow dairy, the savings would be equal to 1 ton per day of corn silage.”

Test results may fluctuate, but it’s focusing on fine-tuning and optimizing the ration with the results that can assist dairy producers in feeding the most economical and cost-effective ration - regardless of the roller coaster ride feed prices take producers on.

For more information call: (800) 635-5701, email: or go to the Calibrate Technologies website.