Efficacy of Solis, NovasilPlus, and MTB-100 to reduce aflatoxin M1 levels in milk of early to mid lactation dairy cows fed aflatoxin B1

An experiment was conducted to determine the efficacy of 3 adsorbents, Solis (SO; Novus International Inc.), NovasilPlus (NOV; Engelhard Corp.), and MTB-100 (MTB; Alltech), in reducing aflatoxin (AF) M-1 concentrations in milk of dairy cows fed an AF-contaminated diet. Twelve early to mid lactation dairy cows averaging 163 d in milk were used in a 4 x 4 Latin square design with 3 replications. Cows were blocked by parity, body weight, and milk production and were provided ad libitum access to feed and water. Within each replicate, cows were randomly assigned to the 4 dietary treatments for 4 consecutive 7-d periods. Dietary treatments included AF [112 mu g of AFB(1)/kg of diet dry matter (DM)]; AF + 0.56% SO; AF + 0.56% NOV; and AF + 0.56% MTB. Milk samples were collected on d 6 and 7 of each of the experimental periods. Feed intake, milk production, milk fat percentage, milk protein percentage, and linear somatic cell scores were not affected by dietary treatments and averaged 22.20 kg/d of DM, 33.87 kg/d, 3.78%, 2.95%, and 1.60, respectively, across all treatments. Transfer rates of AF from feed to milk averaged 2.65, 1.48, 1.42, and 2.52% for cows fed AF, AF + SO, AF + NOV, and AF + MTB, respectively. Daily AFM(1) excretion in milk averaged 66, 37, 35, and 63 mu g/d for cows fed AF, AF + SO, AF + NOV, and AF + MTB, respectively. The addition of SO and NOV to the AF diet resulted in a significant reduction in milk AFM(1) concentrations (SO, 45%; NOV, 48%) and AFM(1) excretion (SO, 44%; NOV, 46%). In contrast, MTB was not effective in reducing milk AFM(1) concentrations (4%), AFM(1) excretion (5%), or AF transfer from feed to milk (2.52%). Results indicated that SO and NOV at 0.56% of the diet were effective in reducing milk AFM(1) concentrations in cows consuming a total mixed ration containing 112 mu g of AFB(1)/kg of diet DM.