2017 has been a challenging year in many parts of the country with excess rain and some widespread flooding. Several of the potential impacts of flooding are forage issue that may remain long after the water has receded.

Potential Forage Hazards:

1. Flood waters may deposit detrimental contaminants on pastures, fields and stored forage. Some of these hazards might include pesticides, dead animals, industrial waste, untreated sewage and silt.
2. Forage harvested after being flooded may still have some of the contaminants present on the lower portion of the forage. Any debris washed into the field, if not removed prior to harvest, may be accidentally baled up in either round bales or square bales. Even clean silt clinging to the forage may increase the ash content of the forage.
3. Stored forage, particularly round bales or the lower level of hay stacks may become saturated with moisture, leading to mold issues and potential organic matter decay.
4. Organic matter that is baled into forage, particularly round bales, may create an opportunity for clostridium botulinum bacteria to multiply anaerobically as the organic matter decays. This bacteria produces the deadly botulism toxin, one of the most potent toxins produced in nature.

Recommendations:

1. Clean and disinfect flooded facilities as soon as possible. Make certain structures are sound before entering to work on them.
2. Remove debris from barnyards, pastures and fields. Unfortunately, no easy solution!
3. Make certain the ground has dried enough to support vehicles before driving in flooded areas.
4. If stacked hay or round bales have been soaked, do not feed the affected bales. If bales must be fed (i.e. emergency forage needs), monitor consumption closely and avoid spoiled areas. If in doubt, throw it out!
5. If harvesting forage from fields that have been flooded and dried out, be very vigilant when mowing and conditioning the forage. You may have to wait a few extra days to allow plants to recover. If there is silt on the lower stem areas, consider leaving longer stubble. Local Agricultural Extension Educators may have specific recommendations for specific locations and for types of rakes that do a better job of reducing ash content.
6. Be extra vigilant when feeding baled forages that have been harvested off of ground that has been flooded.
7. You may want to soil test fields and pastures to see if lime or fertilization will be useful.

If rainfall patterns change, flooding may become more common. Extra vigilance and management may be required to keep horses healthy in these challenging conditions.

Useful Reference: Barnhart, Stephen K. “Summer Flooding of Hay Fields” Integrated Crop Management News, Iowa State University Extension and Outreach, June 2008.

Additional pasture management resources can be found at the University of Minnesota Extension Horse Program website.