|College of Agriculture|
June 20, 2002
Report from Jimmy Henning, Extension
Department of Agronomy
University of Kentucky College of Agriculture
Twelve horse farms and one hay farm are being monitored for several soil, pasture and environmental parameters thought to be related to the MRLS outbreak of 2001. Forage samples are analyzed for fungal mycotoxins, alkaloids associated with tall fescue, cyanide and minerals. Soil samples are checked for populations of yeasts and molds.
As of June 20, all sentinel farms have had 9 or 10 cycles of sampling completed. Data for most assays are complete through the end of May. There have been EFL cases noted in sporadic and low numbers on monitor farms within the last two weeks.
Sample results are summarized below:
Fungal mycotoxins: Small amounts of zearalenone , T2 and DON have been found by ELISA techniques in some samples. Some abnormal or high values for aflatoxin have been found by ELISA techniques that are in the process of being confirmed by thin layer chromatography (TLC). These samples are from both MRLS and non-MRLS fields.
Alkaloids associated with tall fescue: In all but a few cases, alkaloid levels are low and are not a concern. In a few fields, levels of total ergot alkaloids in tall fescue are high enough (>600 ppb) to warrant concern if this tall fescue formed the primary diet for mares in the last 60 days of gestation.
Cyanide in white clover and forage mineral content (including nitrate) are within normal ranges.
Soil microbial counts: Counts for yeasts and molds are variable but within ranges that have been seen across the season. Counts are not correlated with MRLS. Fungi from genera have been found that are known to produce mycotoxins. However, mycotoxin values in forage are below detectable limits or very low for most samples.