ARS | Publication request: Heating effects on the quality of forage

Submitted to: Symposium Proceedings
Publication Type: Proceedings
Publication Acceptance Date: February 25, 2013
Publication Date: March 1, 2013
Citation: Coblentz, W.K. 2013. Heating effects on the quality of forage. Symposium Proceedings. February 28 - March 1, 2013. Burley, ID.

Technical Abstract: The negative consequences of baling forages before they are dried adequately are widely known to hay producers. Generally, these responses include molding, spontaneous heating, losses of DM, and other changes in forage quality that are usually quite undesirable. Many changes in nutritive value are related closely to spontaneous heating incurred within the hay during storage. For hays packaged in small-rectangular (100-lb) bales, these relationships are often linear; however, for larger bale types, linearity with heating may be lost, but the resulting curvilinear responses are still closely associated with heating. Generally, changes in forage nutritive value can occur by direct or indirect mechanisms. An example of a direct response would be the loss of nonstructural carbohydrates (mostly sugars) via respiration. In contrast, fiber components, such as NDF, ADF, etc., increase indirectly as a consequence of heating because these forage components are relatively inert, and their concentrations increase as sugars are oxidized. While most hay producers understand that protein availability within ruminants is reduced with spontaneous heating, they often overlook associated losses of energy. Spontaneous heating has a profoundly negative overall effect on forage quality, and great care should be exercised to properly dehydrate forages prior to baling, thereby avoiding this undesirable phenomenon.