How Good Is My Feed?
We have had our first snowfall and we have some cold weather in the extended forecast. Most beef cattle in the area are still grazing fall pastures, cover crops, or crop residue but it may not be long before producers start feeding hay they have put up this past summer or have purchased. July of 2022 was one of the toughest haying seasons most producers remember regarding the ability to get hay properly cured and dried. As I have traveled around the area I have seen a lot of bales that seemed squashed and out of round indicating that they were either baled with a very low-density setting or they were baled with excessive moisture and may have severe quality issues.
James Rogers is the NDSU Extension Forage Crop Specialist at the North Central Research Extension Center in Minot. Here is an article he wrote regarding moisture content at baling and its effect on feed value.
The moisture content of forage at baling has a direct impact on bale heating and subsequent forage nutrient content at feeding says North Dakota State University Extension forage crops production specialist James Rogers.
“Managing moisture content of forage at baling this year was a challenge,” says Rogers. “For many, it seemed that at the point hay was dry enough to bale, a rain shower would delay baling.”
Controlling moisture at baling can reduce damage to the hay by microorganisms.
“Just like everything that surrounds us, forage plants are covered in microorganisms,” Rogers says. “These organisms survive in either oxygen-rich (aerobic) or oxygen-depleted (anaerobic) environments. When hay is dried to a low moisture content, aerobic organisms cannot survive. If hay is baled when moisture is too high, aerobic organisms survive inside the bale. Since they are living organisms, a food source is required, which they obtain from soluble carbohydrates in plant cells. These organisms also respire, giving off carbon dioxide and generating heat which leads to multiple consequences.”
The moisture content at baling is the number one driver of the severity and duration of bale heating. This relationship between bale moisture content and heating holds true regardless of bale size. However, as bale size and density increase, the intensity of heating tends to increase. For example, if a small rectangular bale and a 5-foot diameter round bale were both baled at 20% moisture content, the round bale would reach a peak higher internal temperature compared to the small rectangular bale.
The results of heat damage to hay nutrient content are multiple. First is the effect it can have on crude protein content. The crude protein content is affected when the nitrogen content of hay (nitrogen x 6.25 = crude protein) becomes linked to carbohydrates through a chemical reaction (Maillard), which is a result of heat generation from baling with high moisture.
Well-cured hays will contain a small percentage of heat-damaged or insoluble protein, but when this percentage is greater than 10%, crude protein needs to be adjusted down to account for the insoluble protein, says Rogers.
A second and often overlooked impact of heating is the reduced energy content of the hay. As aerobic organisms acquire soluble carbohydrates from plant cells, the forage’s energy, often expressed as Total Digestible Nutrient (TDN) content, decreases. When TDN content is lowered, fiber density (neutral detergent and acid detergent fiber) increases. As a result, heat-damaged hay can have reduced crude protein and energy and increased fiber density resulting from excess moisture content and heating. In addition, dry matter loss, visible mold, odors, off colors, and dust often occur with heating that can lead to refusal and respiratory issues in livestock offered heat-damaged hay.
“Controlling moisture at baling is the best way to reduce the potential for heat-damaged hay,” says Rogers. “Target moisture at 20% or less for small square bales and 16% to 18% for large bales. If hay has been baled and moisture content at baling was elevated, test the hay for nutrient content prior to feeding. This gives you an opportunity to adjust supplementation if necessary.”
Another management strategy is proper storage.
“Avoid indoor storage of high-moisture bales as spontaneous combustion can occur,” says Rogers.
When storing outdoors, stack in rows with space between rows to allow for airflow. Store in a way that allows for the escape of excess moisture from hay and a continuation of drying.”
Welcome rainfall this spring and summer has given many livestock producers the opportunity to replenish hay supplies decimated by drought and winter feeding demands. While welcome, the moisture has made hay curing a challenge.
“Moisture content at baling is the main factor in determining bale preservation and nutrient content over time,” says Rogers. “Excessive moisture at baling leads to bale heating and a potential reduction in crude protein and TDN but, an increase in fiber density. The only way to know what these exact losses are is to test. As they say, without a test it is only a guess.”
If you need your hay tested for feed value or a nitrate risk assessment I have a bale probe at the Burke County Extension which producers can borrow or I can meet you and take samples for you. A forage nutritional sample is $18 through Ward Laboratories. If you have forage oat, barley, millet, sorghum, or sudan bales and would like to participate in the Nitrate Risk Assessment Program by providing information about your production practices I can get your nitrates checked at no charge and get a 30% discount on the feed value analysis. Contact the NDSU Extension/Burke County office at 701-377-2927