Farms.com Home   News

The Cost of a Windrow

By Dan Undersander
 
When harvesting hay or haylage we tend to think in terms of how long it takes to get the hay off the field. However, the first concern for quality hay/haylage should be how long it takes to lose the first 15-20% moisture. Forages have 75-80% moisture when cut; they will continue to respire sugars (break down and give off heat and carbon dioxide) at a high rate until the plant is dried to 60% moisture. If we want to save the energy of the starch and sugars for our cattle, we need to dry off the first 15-20% moisture as quickly as possible.
 
Most of the respiration takes place in the leaves. We should remember that conditioning is for drying the stems but has little impact on drying the leaves.
 
A wide swath has the biggest effect on rate of leaf drying. Leaves dry faster in a wide swath because:
  • More sunlight falling on the field is intercepted for drying. (A windrow intercepts only 25-30% of sunlight falling on the field while a wide swath intercepts 70-100% of sunlight.)
  • Light keeps the leaf stomates open longer, so moisture can leave through leaf openings. Since most of the forage in a windrow is in the dark, the leaf stomates close to seal the leaf surface.
Table 1 shows the losses that can occur due to making a windrow rather than a wide swath. Data indicate that starch and sugar loss can range from 2-8% of dry matter. If we assume a median starch/sugar loss of 4% of dry matter due to hay in a windrow compared to a wide swath, then the dry matter economic loss is $6.40/ton, according to current hay prices in the Midwest for large square bales.
 
 
However, the respiratory losses of starch and sugar also increase the fiber content of the forage. If the forage was near 40% NDF (prime hay/haylage) when cut, then the 4% starch loss will increase fiber 3.4 units and lower the quality to Grade 1 hay (125-150 RFQ). Grade 1 hay is currently selling for $38/ton less than Prime hay. The value to dairy producers is about twice the price differential between hay grades.
 
Many farmers have switched to making wide swaths when mowing. A wide swath is the single most important factor affecting forage drying rate; it is more important than conditioning. Farmers who continue to put hay into windrows are increasing drying time and risk of rain damage. They are also currently losing about $44.40/ton due to yield and quality losses from increased respiration. Considering this dollar loss, most farmers could figure out a way to make wider swaths with their existing equipment; they should also look at wide swath mowers when replacing mowing equipment.
 

Trending Video

Secure Your Pig Herd with AgView | Streamline Disease Defense with Traceability

Video: Secure Your Pig Herd with AgView | Streamline Disease Defense with Traceability

Join Jill Brokaw, a third-generation pig farmer and staff member of the National Pork Board, as she dives into a resource developed by the National Pork Board, paid for with Pork Checkoff funds. AgView is a pivotal tool, enabling swift and efficient responses to potential foreign animal disease outbreaks by allowing producers to securely share location and pig movement data with State Animal Health Officials to rapidly contain the disease threat and determine where the disease is or is not present.

Why Should Pork Producers Care? AgView standardizes and streamlines how America's pig farmers communicate information to animal health officials that supports business continuity in an outbreak. It is an entirely voluntary tool where you continue to own and control your data.

Getting Started with AgView: Getting started is incredibly easy. You can access the platform on any device. Producers can upload data directly to their AgView Account or work with the National Pork Board to connect the platform using an application programming interface or API.

Takeaway: AgView was built to be the path to protection that helps producers and officials respond to a foreign animal disease emergency the minute a threat arises, providing the critical information needed to manage a foreign disease crisis.