He has been a consultant to Alltech for 12 years, and was in this country late last year meeting with feed suppliers.
Smith said there were many sources of mycotoxins in different animal feeds which could cause liver damage and suppress immunity.
“The real challenge is lingering problems such as failure of vaccinations which can result in mortalities, which can be indirectly caused by contaminated feed. Management systems such as high density housing can also contribute.”
Recent research has shown that there may in fact be a double whammy effect, with mycotoxin fungi being present in more than one form. Methodology which has been used to detect mycotoxins might have underestimated levels by half as only they were measured, not the plant defence mechanism which might boost levels further. This advance was significant because “it helps explain past mysteries”.
Smith said methodology was being worked on at present with the aim of producing a simple, low-cost diagnostic test farmers could use in the field which would allow for toxins not being evenly distributed throughout the feed.
He usually visits NZ every couple of years and said it was interesting to see changes in feeding systems with many farmers moving from pasture to concentrates and blends.