In vivo release of aflatoxin B1 bound to different sequestering agents in dairy cows

Nine lactating dairy cows, producing 31.08±5.00 kg of milk/cow/day and fed with a Total Mixed Ration (TMR) with an intake of 22.3±0.8 Kg s.s./cow, were used to investigate the resistance of the AFs-SA complex in the rumen and in the gastro-intestinal tract. Two commercial sequestering agents Atox® and Mycosorb® were used. The AFB1 was also mixed to a rumen fluid (R-SA). AFB1 sequestered by Atox® , Mycosorb® and by R-SA were then fed to cows before the morning meal. Milk samples were collected for 6 consecutive milkings and analyzed for AFM1 content. The in vitro binding capacity of the two SA were 94.2% for Atox® , 84.3% for Mycosorb® and 71.86% for the R-SA. Both Atox® and Mycosorb® released some of the sequestered AFB1 determining an increase of the AFM1 in milk as soon as in the 1st milking from oral drenching (4.23±7.33; 23.60±8.23 and 46.06±39.84 ppt for Atox® , Mycosorb® and R-SA respectively). The AFM1 (ng/cow) in milk at the 4th milking was lower (66.04, 661.77 and 1613.04; P<0.05) in Atox® and Mycosorb® than R-SA, respectively. The percentage release of bound AFB1 were 1.63% for Atox® , 20.27% for Mycosorb® and 50.48% for R-SA.