The study showed strong evidence to support its findings about reducing feeding, Paterson said.

If you are in Texas and are paying $300 a ton for hay, a 20 percent savings in forage is huge," he commented. "That's a huge savings especially in a drought environment where you are trying to save feed, or hay is really expensive."

Neither Waterman nor Paterson said they could predict if producers will decide to reduce the amount of feed delivered to heifers based on this study.

Paterson said Montana beef producers treat their animals very well, so, if they have plenty of rain and hay, they may decide to continue feeding their animals all they want.

But producers who live in Texas, New Mexico and other states hit by drought may be relieved to learn they won't hurt their heifers by feeding them less during the development stage, Paterson said.

Researchers in the Fort Keogh study came to their findings, in part, by administering two tests that measure how efficiently a heifer turns feed into energy.

One test was a glucose tolerance test, and the other was an acetate irreversible loss test. Acetate — a secondary energy source for cows — is produced by fermentation in the rumen. One goal of the study was to see how fast the acetate disappeared from the blood stream and was used for energy.

The scientists administered the two tests at the end of the 140-day development period and again when the heifers were pregnant with their second calves.

During the second test, the heifers were no longer in confinement, but they were grazing dormant forage on rangeland.

A previous Fort Keogh study found that animals use nutrients differently depending on the time of year, Waterman said. The worst time is fall and winter, when range forage is dormant. Nutrients at that time can't enter the heifers' cells as efficiently as at other times.

Waterman said the heifer study was unique and valuable to producers for a couple of reasons.

For one, it was part of a long-term beef productivity study that Fort Keogh scientists started in 2002.

For another, the study included the treatment of the heifers when they were fetuses.

Members of the Fort Keogh team that conducted the heifer nutrition study, in addition to Waterman, were Andrew Roberts, Thomas Geary, Elaine Grings (now at the International Livestock Research Institute in Nigeria), Leeson Alexander and Michael MacNeil.

Fort Keogh is a USDA-Agriculture Research Service rangeland beef cattle research facility. It is run in cooperation with the Montana Agricultural Experiment Station, an agriculture research component of MSU