Effects of Rain Damage on Wilting Forages

One of the most common problems faced by hay or silage producers is how to manage production schedules around unfavorable weather. Inevitably, some wilting forage crops are damaged by rainfall each year, and producers often inquire about the effects of rain damage, and what impact this may have on forage quality, silage fermentation, and animal performance. Actually, the problem is more complex than damage to wilting forage crops via leaching, extended or reactivated plant respiration, and/or leaf shatter. Common consequences of uncooperative weather also may include: i) spontaneous heating and/or combustion that occurs when producers try to complete baling operations of incompletely wilted hays prior to an oncoming rainfall event; ii) poor silage fermentation; and iii) excessively mature forage that results from delaying haying or silage harvesting operations until weather is more favorable. Maturity effects on forage quality can be as severe as spontaneous heating and/or rain damage.