Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: November 20, 2007
Publication Date: December 12, 2007
Citation: Coblentz, W.K. 2007. Biology and Effects of Spontaneous Heating in Hay. Proceedings of the 11th Annual University of Wisconsin Arlington Dairy Day, December 12, 2007, Arlington, WI. Technical Abstract: The negative consequences of baling hay before it is adequately dried are widely known to producers. Frequently, these problems are created by uncooperative weather conditions that prevent forages from drying (rapidly) to moisture levels that allow safe and stable storage of harvested forages. When baling occurs before forage is dried adequately, a number of undesirable responses are often observed. These include molding, spontaneous heating, reduced forage quality, and the potential for spontaneous combustion. The magnitude and duration of spontaneous heating is affected by numerous factors, including forage moisture content, bale size, bale density, climatic conditions, and use of preservatives. Most changes in nutritive value, including estimates of ruminal protein degradation and the associated ruminal decay rate, are related to spontaneous heating in surprisingly close linear relationships. Spontaneous heating has a profoundly negative effect on forage quality, and great care should be exercised to ensure that forages are dehydrated properly prior to baling.