Relationship between contamination of mycotoxin in feeds and the productivity of dairy cows

The concentrations of aflatoxin Bsub(1) (AFBsub(1)), deoxynivalenol (DON) and zealarenone (ZEN) in commercially available feeds and farm-prepared roughages were determined to investigate the relation to the productivity in dairy farms. Concentrations of AFBsub(1), DON and ZEN in commercially available feeds and farm-prepared roughages were within the approved levels, however, some farm-prepared roughages showed excess over the approved levels. Decreased milk yields and increased cull rates appeared to be associated with increased levels of AFBsub(1) in farm-prepared roughages from dairy farms. This relation was found to be more apparent in dairy farms where one-kind of farm-prepared roughages was supplied to the dairy cows than the dairy farms in which two-kind of roughages and commercially available feeds were given to the dairy cows. From these results it has been considered that mycotoxin in feeds may be associated with farm-prepared roughages, and particularly AFBsub(1) affects more clearly the productivity of dairy cows.