Effects of adsorbent on milk aflatoxin M1 and lactation performance of dairy cows exposed to long-term challenge of aflatoxin B1

Abstract Text: The objective of the study was to evaluate the effects of adsorbent on milk aflatoxin (AF) M1 and lactation performance of dairy cows exposed to long-term challenge of AFB1. Forty dairy cows were blocked based on days in milk (33 ± 7; mean ± SD) and milk production (33.9 ± 3.1 kg; mean ± SD), and were randomly assigned to 1 of 4 treatments in a 2 × 2 factorial arrangements with AFB1 (0 or 20 μg/kgDM) and Solis Mos (Novus International Inc., 0 or 0.25% of DM). The experiment lasted 9 weeks, with the first week for adaptation. Milk yield and milk composition were recorded weekly, and serum concentrations of biochemical and antioxidant variables were analyzed in the first and the last week of the experiment. Milk AFM1 was analyzed by HPLC-MS/MS. Variables of data were analyzed using the mixed procedure of SAS. Dry matter intake, milk yield, contents of milk protein and milk fat, and linear somatic cell count averaged 23.9 kg/d, 35.5 kg/d, 2.9%, 3.6%, and 5.1, respectively and were not affected (P > 0.05) by either AFB1 or Solis Mos supplement. Addition of Solis Mos in AFB1-contaminated diet significantly reduced (P < 0.01) milk AFM1 concentration (0.19 vs. 0.13 μg/kg) and transfer rates (1.38 vs. 0.89 %). Dairy cows fed AFB1-contaminated diet had lower level of superoxide dismutase activity, total antioxidant capacity, glutathione peroxidase, IgG and IgA (P < 0.05), and higher level of malondialdehyde in plasma (P < 0.05). Inclusion of Solis Mos into diets increased the plasma superoxide dismutase activity, total antioxidant capacity, and IgG, while deceased malondialdehyde (P<0.05). Neither AFB1 nor Solis Mos affected (P > 0.05) the plasma levels of alanine transaminase, aspartate aminotransferase, and alkaline phosphatase and IgM. It is concluded that inclusion of Solis Mos did not affect lactation performance, but reduced milk AFM1 concentration and transfer rate, and increased antioxidant capacity and immunity in early-lactating dairy cows exposed to long-term challenge of AFB1.

Keywords: adsorbent, aflatoxin, transfer