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High-quality hay more than pays for itself

We all know high-quality forage is a must for maximum production of milk and milk components. Adequate roughage is needed for good rumen function. But as more roughage is fed, diet energy density is reduced.

That’s why it’s so crucial to pack maximum energy in every bale and ton at harvest. Easier said than done, right?

In the Northeast’s climate, it’s hard to find a wide time window to mow, dry, and either chop or bale hay crops. However, recent advances in forage harvesting equipment claim to reduce the amount of time between mowing and storage.

And that’s great! The need for rapid wilting or drying of forage crops in the field is well recognized.

Key Points

Speedy curing of hay crop cuts the amount of feed nutrients you have to buy.

Drydown must remove about 3 tons of moisture per ton of hay.

Rain damage is less if right after cutting, than just before baling.


When a high-yield crop is laid in a narrow swath, swath size slows drydown. When forage is spread in a thin swath, the movement of moisture out of the plant can become limiting. Under these circumstances, conditioning of the crop is most beneficial.

Warm air temperature and low humidity aids drying. The sun still is the primary drying force. Wet soil under the swath also slows drying by allowing moisture to move up into the swath.

Hay drying requires removing about 3 tons of moisture for every ton of hay. Be skeptical when you hear of new, miraculous and inexpensive processes that can dry hay without the sun.

What happens while you wait

Dry matter losses and quality changes occur while your crop is wilting or drying in the field. Plant respiration converts carbohydrates stored in the plant tissue to carbon dioxide, heat and moisture that leave the plant, causing a DM loss.

Plant respiration ceases once moisture levels fall below 40%, so rapid drying early in the field curing process reduces this loss. That loss is primarily readily digestible carbohydrates.

That means you’re also losing fiber and energy content. With rapid drying, this loss is less than 5%. But it can be excessive under poor drying conditions.

Rain damage has the greatest effect. It knocks off leaves and leaches out soluble carbohydrates, proteins and minerals, leaving a material with higher fiber and lower energy value.

The goal is always to avoid rain damage. But it’s better to have it early in the drying process rather than about the time the crop is ready to bale. You might argue that this is somewhat beyond our control. But be less concerned about rain on the day of mowing if better weather lies ahead.

Baling hay before its dry — near 25% moisture — is another way to reduce field losses. It may reduce raking and baling losses and increase harvested yield about 7%, plus boost harvested quality. However, it deteriorates rapidly in storage unless it is treated to enhance preservation or wrapped as baleage.

In haymaking, mechanical conditioning should be used, and high-yielding crops should be spread in wide swaths. In silage making, drying is a little less critical.

Wilting in narrow swaths can reduce raking loss, particularly for low-yielding cuttings. Rakes or mergers can be used to improve machine harvest capacity. A substantial economic benefit can often be obtained by rolling swaths together to allow large balers or forage harvesters to operate more efficiently.

Carson and husband Steve partner in Harkdale Farms of Newbury, Vt.

When to use various hay drying tools

Mechanical hay conditioning speeds drying and reduces dry matter and nutrient losses. But while the severity of conditioning can speed field curing, it can also increase harvest losses.

Normally, moderate conditioning is recommended to obtain adequate drying with relatively low loss (1% to 2% of yield). This relatively low loss has little effect on forage quality. Swath manipulation by tedding, swath inversion or raking can speed the process by increasing exposure to radiant solar energy and drying air. Consider the pros and cons of each:

Tedding. This method typically reduces field-curing time up to a half-day. Tedders are sometimes used to spread a narrow swath formed by the mower-conditioner over the entire field surface. When done soon after mowing, the average field curing time is reduced up to two days, compared to drying in a narrow swath. It also tends to create more uniform drying, so wet spots in the swath are reduced. Its disadvantages include increased losses and increased fuel, labor and machinery costs. Done on a relatively wet crop (above 50% moisture), the resulting loss is less than 3%. Done late in the drying process, losses can be more than 10%. Tedding may be useful in drying grass crops, but should be avoided with alfalfa, particularly after the crop has partially dried. Comparing tedding’s costs to benefits, routine use is difficult to justify, especially for alfalfa.

Swath inversion. These machines gently lift and invert the swath. Exposing the wetter bottom of the swath speeds drying and reduces average field-curing by a few hours. Swath inversion isn’t as effective for improving drying as tedding, but shatter loss is very low. With less drying benefit, there is less potential for reducing rain and respiration losses. Again, the added labor, fuel and machinery costs are generally greater than the benefit received.

Raking. This method also changes swath width and tends to roll wetter hay from the bottom of the swath to the outer surface to improve drying. But the increase in swath density can reduce drying rate, so moisture content at raking is important. Raking losses are related to crop moisture (2% when wet to 15% in a very dry crop). The best moisture content to rake for low loss and good drying is between 30% and 40%.


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MONEY IN THE BANK: No matter whether hay goes — to the bale, bag or bunker — speedy drydown and curing is worth more now than ever before as a feed ingredient.

This article published in the August, 2012 edition of WESTERN FARMER-STOCKMAN.

All rights reserved. Copyright Farm Progress Cos. 2012.