Total mixed rations (TMRs) can increase feed efficiency in dairy herds, but must be properly managed, says Alvaro Garcia, South Dakota State University extension dairy specialist.

Some of the most common TMR management errors, says Garcia, include feeding a partial TMR, trying to mix in too much hay, feeding batches that are too small, or trying to exceed the mixer's capacity.

Avoid too much or too little mixing time, he advises.

“The goal is for the TMR to consist of 8-10% coarse particles,” he says. “Studies have shown that mixing the TMR for longer than 15 minutes can reduce the amount of coarse particles to less than 5% of the ration.”

Five minutes of actual mixing time is usually enough, he adds.

All ration components should be analyzed for moisture, crude protein and energy content. Something that might seem inconsequential can have a big impact on production.

For example, a mistake of just four percentage points in the moisture content of corn silage can cost up to 3.5 lbs/cow/day in milk production.

Moisture content is crucial. A TMR should contain roughly 50% moisture. It can be increased by adding water or including moist feeds such as silage or wet distillers grain.

Avoid producing a TMR that's prone to sorting, says Garcia. He lists three options for combating sorting problems: process corn silage as it's chopped, add less and/or higher-quality hay to the mix, or add liquid molasses.