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Is Your Hay Cut Right but Baled Wrong?

ARDMORE, Okla. — The cost of producing hay drives many producers toward maximizing hay yields in order to distribute cost over more production. This often lowers forage quality because a more mature forage plant is being harvested. Supplementing lower-quality forages to meet livestock nutritional demands then adds indirect cost back to hay.

"This is why we advocate cutting forages at the proper stage of maturity, based on species, to reach a compromise between yield and quality," said James Rogers, forage specialist with the Noble Foundation.

But what if you get your hay "cut right" but "baled wrong" (meaning baled at a too-high moisture content)?

"Obviously, one result could be that bales catch fire along with a storage facility, but this is not always the case," Rogers said. "If you are pushing the moisture edge a little bit because you are trying to prevent leaf shatter or move on to another chore, you may not have realized that the hay was put up with extra moisture."

What then happens to that bale after it sits in storage for a while?

Recently published work from the University of Arkansas looked at the effects moisture content has on quality characteristics of bermudagrass small square hay bales stored for a period of 60 days. Changes in temperature, dry matter content, nitrogen concentration, fiber concentration, visible mold and digestibility were evaluated.

In the study, Greenfield bermudagrass hay was baled at moisture content treatments of 17.8, 20.8, 24.8, 28.7 or 32.5 percent. Bales were weighed and sampled to determine initial moisture and nutritive content prior to placement in a storage facility.

"As expected, higher-moisture bales had higher maximum temperatures and higher 30-day average temperatures than lower moisture bales," Rogers said. "Combining higher moisture and temperature resulted in significantly greater mold ratings and less dry matter recovery than lower moisture bales."

Dry matter recovery was determined as a percentage of dry matter weights of bales before and after storage.

In assessing changes in quality, bales made at lower moisture levels (17.8%, 20.8%) showed very little change in acid detergent or neutral detergent fiber (ADF, NDF), in vitro dry matter digestibility (IVDMD), nitrogen (N) or acid detergent insoluble nitrogen (ADIN-N) from pre-storage measurements. This would suggest that at these moisture levels little change would occur in forage intake, digestibility or protein content.

"However, as bale moisture levels rose, ADF and NDF concentrations increased, digestibility decreased, total N increased slightly and ADIN-N increased when compared to pre-storage levels on a dry matter basis," Rogers said.

The take-home message is this: Make sure hay is dry enough to bale.

"If not, bermudagrass baled at moisture contents higher than 21 percent can have significant increases in fiber concentrations and insoluble N (heat-damaged N) and decreased digestibility," Rogers said. "And similar effects have been reported for alfalfa hay as well."

If in doubt, test moisture content using the microwave method, moisture tester or some other means, he added.

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The Samuel Roberts Noble Foundation, headquartered in Ardmore, Okla., is a non-profit organization conducting agricultural, forage biotechnological, and plant biology research; providing grants to numerous non-profit charitable, educational and health organizations; and assisting farmers and ranchers through educational and consultative agricultural programs.

To learn more, visit the Noble Foundation Web site at http://www.noble.org.

More news releases available at www.noble.org/Press_Release