Reducing hay harvest losses

Greg Lardy
Department Head, NDSU Animal Sciences
Greg Lardy |

Haying season is underway. By paying attention to the details when harvesting, you will be able to reduce loss and produce the highest quality hay possible for your operation, making the most of your investment in equipment and other inputs.

Conditioning – Conditioning is a way to speed up legume drying by opening the waxy layer surrounding the stem. Large or coarse stemmed hays tend to respond to conditioning better than fine stemmed hays. Be sure to read the manufacturer’s recommendations for proper adjustments to your conditioning equipment for the type of forage you are cutting.

Raking – Avoid raking alfalfa when the forage moisture content is less than 40 percent. This practice can reduce leaf loss more than any other harvesting activity. Leaves are the most nutritionally dense portion of the plant.

Weather related losses – Leaching, caused by rainfall, can result in up to 20 percent nutrient loss. Carbohydrates, B vitamins, and some soluble minerals are readily leached from dry hay when it is rained on. Be sure to plan hay harvesting around major weather systems when possible.

Time of cutting – Natural physiological processes in plants cause the concentrations of soluble carbohydrates and other highly digestible nutrients to peak in the evening. Research suggests that hay cut at or near sundown is higher in energy than hay harvested at sunup.

Hay moisture content – The single most contributing factor to leaf loss is hay moisture content. Hay baled above 15 percent moisture has the least amount of leaf loss. Large round hay bales should be between 18 and 20 percent moisture to prevent mold growth and other deterioration. Hay baled above 25 percent moisture will usually spoil unless chemical preservatives are added. The risk of fire increases if hay is put up too wet and stored indoors as the hay may begin to heat and could spontaneously combust.

When hay becomes too dry and brittle and losses become excessive on any given day, discontinue baling and resume later in the evening or the next morning when leaf moisture level is increased. If you continued baling in the morning, be aware that when dew is present, moisture gauges will tend to err on the high side resulting in a somewhat higher number than the actual internal moisture content of the hay. However, dew moisture in hay is more easily released during curing than internal moisture.

A number of commercial moisture testers are available. Some operate using a sample of hay, while others operate using a probe. Generally, the probe models are simpler to use since they do not require taking a sample. Take a number of readings and average them to get the most accurate moisture determination. Be sure to probe several bales at different locations in the field to account for variation within the field. Square bales should be probed from their ends while round bales should be probed through their diameter.

Baler pickup – The pickup mechanism of large round balers may cause losses as high as 12 percent, although losses more typically range from one to three percent. Field speed of the baler, size of the windrow, hay moisture content, and mechanical condition of the pickup devise influence this loss. Higher moisture content reduces pickup loss. Lowering field speed in general, and synchronizing field speed to pickup rotational speed in particular, reduces pickup loss. Heavy windrows reduce pickup loss by reducing field speed and contact with pickup components.

Bale chamber – Bale chamber losses have been measured as high as 18 percent for large round balers. Bale chamber losses are normally two or three times higher in a large round baler than a rectangular baler. Windrow size, field speed, hay moisture content, bale rotation speed, and wrapping of twine or netting contribute to chamber losses.

To minimize bale chamber losses, the moisture content should be as high as possible to permit safe storage and the baler feeder rate should be as high as possible to minimize the number of turns within the bale chamber. Where windrows are small or field speeds must be low, use a lower PTO speed. This results in fewer revolutions to form a bale.

When wrapping twine, do not rotate the bale more times than necessary to secure the twine. The leaves which fall from the bale chamber during twine wrapping are an indication of the bale chamber loss.


This article would not be complete without mentioning the need for safety. Be sure to read and adhere to all of the manufacturer’s guidance related to safety and safety equipment with your haying equipment. Remember to shut down all equipment before making any adjustments or performing any maintenance. In addition, be sure to be well rested when operating equipment.


There are a variety of factors which contribute to field losses during cutting and baling hay. Paying attention to these factors will allow you to reduce potential field losses, harvest a higher quality forage product, and improve overall economics of your haying operation. Best of luck with your haying season this year and remember, above all else, keep safety in mind when working around haying equipment.

Portions of this article adapted from AS-1190, “Minimizing Hay Losses and Waste.”