Reduction of carryover of aflatoxin from cow feed to milk by addition of activated carbons

According to a double-reversal experimental design on 12 late-lactation Friesian cows the effect of two activated carbons (ACs) (CAC1 and CAC2) and a hydrated sodium calcium alumino-silicate (HSCAS) on carryover of aflatoxin B-1 (AFB(1)) from feed to aflatoxin M(1) (AFM(1)) in milk was determined. Cows were fed a basal diet containing AFB(1) naturally contaminated corn meal and copra. During week 1 cows were fed diets containing AFB 1 alone (11.28 mu g of AFB(1)/kg of feed); in week 2 the diets contained AFB(1) plus 2.0% sorbent; and in week 3 the diets again contained AFB(1) alone (13.43 mu g of AFB(1)/kg of feed). ACs reduced the analytical content of AFB(1) in the pelleted feed by from 40.6% to 73.6%, whereas reduction by HSCAS was 59.2%. The AFM(1) concentrations in milk in weeks I and 3 were higher than that in week 2, Decreases in the AFM(1) excreted in the milk by addition to feed of 2% of the sorbents ranged from 22% to 45%. CAC1 and HSCAS were significantly different from each other in reducing the AFM(1) concentration in milk (45.3% versus 32.5%); these reductions were significantly higher than that of CAC2 (22.0%). Carryover reduction by addition of CAC1 (50%) was significantly higher than that of HSCAS (36%). Addition of 2% CAC2 did not allow pelleting of feed because of the caking action of this carbon. The lower performance of CAC2 could be related to the unsuccessful pelleting. The addition of ACs did not influence feed intake, milk production, milk composition, or body weight. Our results suggest that ACs, high-affinity sorbents for AFB(1) in vitro, are efficacious in reducing AFB(1) carryover from cow feed to milk. Further in vivo investigations should establish lower amounts of ACs which can be efficacious.