Carryover of Aflatoxin M_t in Milk of Cows Fed Aflatoxin B₁ CONTAMINATED RATION

Ten crossbred cows yielding 8–101 milk/day were fed 25, 50, 75 and 100ppb anatoxin B₁(AFB1) through concentrate mixture alongwith green maize and wheat straw which contained non-detectable level of AFB₁. On an average, cows consumed 71–25, 150, 229.5 and 293.0 ng AFB_t daily through their concentrate mixture and excreted 0.047, 0.068, 0.112 and 0.265 µg AFM₁/kg milk, respectively, at maximum excretion- AFM₁ excretion in milk reached its maximum and stabilized after 6 to 9 d from start of feeding 25, 50, 75 and 100 ppb contaminated concentrate mixture and excretion rate from feed (AFB₁) to milk (AFM₁) was 0.634, 0.391, 0.424 and 0.586 percent, respectively. After complete withdrawal of AFB₁ contaminated ration, AFM₁ excretion in milk of cows dropped to a negligible level (<0.01 µg/1) with in 4–5 d.