A simple steady-state model for carry-over of aflatoxins from feed to cow's milk

A simple steady-state model is derived from two kinetic one-compartment models for the disposition of aflatoxin B-1 (AFB(1)) and aflatoxin M-1 (AFM(1)) in the lactating cow. The model relates daily intake of AFB(1) in feed of dairy cattle and the cow's lactation status to resulting concentrations of AFM(1) in milk. Moreover, assuming a linear relationship between the cow's lactation status and feed intake, the model relates daily milk production and AFB(1) concentration in total feed to AFM(1) levels in milk. The model explains similar experimental outcomes from different investigations into carry-over of aflatoxins from feed to milk. Although it is difficult to set a permanent limit for AFB(1) in feed, the European Union (EU) limit of 5 mu g AFB(1) kg(-1) concentrate has proved, thus far, to be an appropriate level in preventing the EU limit of 0.05 mu g AFM(1) kg(-1) milk being exceeded.