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ARS Home » Midwest Area » Madison, Wisconsin » U.S. Dairy Forage Research Center » Research » Publications at this Location » Publication #202128

Title: Rain Damage and Spontaneous Heating in Southern Forages Harvested as Hay

Author
item Coblentz, Wayne

Submitted to: Southern Pasture and Forage Crop Improvement Conference Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 3/31/2006
Publication Date: 4/13/2006
Citation: Coblentz, W.K. 2006. Rain Damage and Spontaneous Heating in Southern Forages Harvested as Hay. In: Proceedings of the 60th Southern Pasture and Forage Crop Improvement Conference, April 11-13, 2006, Auburn, Alabama. 2006 CDROM.

Interpretive Summary: Given the uncertainty of the weather and inherent differences between forages, recommendations for avoiding or limiting rain damage are not consistent across specific forage crops. For tall fescue, results of experiments at the University of Arkansas indicate that the damage created by a single rainfall event of approximately 1-inch is not excessive, particularly when compared to the consequences of spontaneous heating, or the rapid negative changes in forage quality that occur when harvest is delayed. This suggests that producers could be more aggressive during the late-spring with fairly limited risk. Orchardgrass and legumes may be more susceptible to rain damage, and may need to be managed more conservatively. In contrast, the quality characteristics of bermudagrass (and likely other perennial warm-season grasses) are only affected minimally by rainfall events; however, this may be less important because weather patterns usually become more stable during summer months. Although there are relatively few studies assessing the impacts of rain damage on voluntary intake of hay by livestock, these studies suggest that a 10% reduction in voluntary dry matter intake by cattle in response to a soaking rain may serve as a good 'rule of thumb' until additional studies are conducted.

Technical Abstract: Given the uncertainty of the weather and inherent differences between forage crops, specific recommendations for managing potential rain damage to wilting forages are difficult. However, there are a number of principles that can be applied to best manage the potential for rain damage. These science-based principles and their interaction with specific forage crops are described in detail, thereby allowing producers to make more informed management decisions. Although there are relatively few studies assessing the impacts of rain damage on voluntary intake of hay by livestock, these studies suggest that a 10% reduction in response to a soaking rain may serve as a good 'rule of thumb' until additional studies are conducted.