Chemical Composition and Nutritive Value of Corn Silage Affected By Hurricane Irene.

In the Fall of 2011, Hurricane Irene caused significant damage to a major proportion of the forage corn crop in the Northeast region of the United States.  Compromised crops were subjected to various degrees of flooding, lodging and contamination with silt. The objective of this study was to determine if affected plants harvested for silage fermented normally and if the nutritive value of these silages was nutritionally compromised in any way.  The chemical and nutrient composition of affected silages were compared to that from silages made from unaffected plants from the same region. The concentration of NE_L and in vitro digestibility of NDF were lower in plants affected by the hurricane.  In addition, the ash content of compromised silages was higher than in unaffected silages.  Specifically, concentrations of Al, Co, Mn, and Fe were higher in affected silages.  Concentrations of Fe and Al were as high as 12,534 and 4,410 ppm, respectively in silage from a flooded field.  Silage fermentation appeared to be normal as  the final silage pH, and concentrations of fermentation acids, alcohols, and esters were similar between compromised and unaffected silages.  Numbers of yeasts (but not molds) tended to be higher in compromised silage than in unaffected silage.  Pathogenic microorganisms were not detected in any silage and concentrations of mycotoxins were not adversely affected by the storm damage.  More than 40% of the farms that fed flood-damaged corn silage reported animal health impacts including: reduced dry-matter intake, digestive upset, reduced milk fat, reduced lactation, elevated somatic cell count, reduced conception rate, increased rate of abortion, and cow death.