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How to interpret your forage test report

Whether you do it by looks, feel and smell, or whether you ask for a forage test if you’re buying hay, you need to know if you’re getting your money’s worth before you buy the first bale.

This could be a year when quality hay fetches a premium, since later cuttings of legumes suffered from lack of rain.

Chris Parker, Morgan County Extension ag educator, says looks can be deceiving. Quite often, hay that’s bleached and brown still tests well, he notes. “They don’t test for vitamins, and that’s the main thing that’s lost. Otherwise, the hay may test well on protein, low in fiber and have lots of energy. It could still be a very good buy if the price is right.”

There are a couple of other factors lab tests may not pick up. One is weeds in the hay. If you examine hay and find weeds, especially mature weeds with seeds or noxious weeds, like thistles, be cautious. There’s still a place for it, perhaps feeding beef cattle, but you need to realize that weeds in the bale detract from overall value of the hay.

Key Points

Looks and smell can get you in the ballpark on several measurements.

Bleached hay may still be a good feed if you supplement it with vitamins.

Protein, fiber, energy and relative feed value are the critical numbers on reports.

Second, how does the hay smell? Hay with a musty odor in the summer may be the hay that exudes white, powdery dust when you cut bales open next winter. It’s typically a mold that can grow if the hay is baled damp. It may not affect test results, and unless it’s extreme, may still be OK to feed. However, you may not want to buy it for pregnant animals in the later stages of pregnancy.

Interpret lab results

If you send in samples for testing, here are hints to look for, Parker says.

Moisture content. Hay will typically test around 15% to 20% moisture. That usually makes for more palatable hay than hay that’s very dry. To know what’s truly in the hay on an apples-to-apples basis, check the dry matter basis column.

Crude protein. This number will get you in the ballpark. Other information about protein shows on the report, including percentage of heat-damaged protein and available protein. For most purposes, crude protein tells you what you need to know.

Crude fiber. Chemists talk about acid detergent fiber and neutral detergent fiber. The bottom line is how much crude fiber the hay contains, Parker notes. The later the hay is cut, the more fiber it will likely contain. High crude fiber numbers don’t matter if it’s a beef animal or dry cow on maintenance, but can detract from overall feed value if you need lots of energy.

Total digestible nutrients. This is an estimate of how many digestible nutrients are actually in the hay. It’s an indirect measure of energy.

Relative feed value. This is a calculated number, not a percentage. It’s based on the factors mentioned here, plus more. A base of 100 represents average hay for feeding value. Those bales lower than 100 don’t have as much feeding value. However, there is still a place for them. Just make sure you don’t pay top dollar for hay that might not meet the standard relative feed value.


Real fooler:This bleached hay could still be a bargain at the right price. However, you would need to supplement it with vitamins.

This article published in the October, 2011 edition of INDIANA PRAIRIE FARMER.

All rights reserved. Copyright Farm Progress Cos. 2011.