Efficacy of Bacillus subtilis ANSB060 Biodegradation Product for the Reduction of the Milk Aflatoxin M1 Content of Dairy Cows Exposed to Aflatoxin B1

This study was conducted to determine the effect of Bacillus subtilis ANSB060 biodegradation product (BDP) in reducing the milk aflatoxin M-1 (AFM(1)) content of dairy cows fed a diet contaminated with aflatoxin B-1 (AFB(1)). Twenty-four Chinese Holstein cows (254 +/- 19 d in milk; milk production 19.0 +/- 1.2 kg d(-1)) were assigned to three dietary treatments, as follows: (1) control diet (CON), consisting of a basal total mixed ration (TMR); (2) aflatoxin diet (AF), containing CON plus 63 mu g of AFB(1) kg(-1) of diet dry matter; and (3) aflatoxin diet plus BDP (AF + BDP), containing AF plus BDP at 0.2% of diet dry matter. The experiment lasted 12 days, including an AFB(1)-dosing period from days one to eight, followed by a clearance period from days nine to twelve. Milk samples were collected on days 2, 4, 6, and 8-12, and the plasma was sampled on day 9, before morning feeding. Short-term AFB(1) exposure did not affect the milk production and composition. The plasma biochemical indices, except for lactic dehydrogenase (LDH), were also not changed by the AFB(1) intake. The plasma LDH level was significantly elevated (p < 0.05) following dietary treatment with AFB(1), while no significant difference was observed between the AF + BDP and CON treatments. Adding BDP to the AFB(1)-contaminaed diet resulted in a significant reduction in AFM(1) concentration (483 vs. 665 ng L-1) in the milk, AFM(1) excretion (9.14 vs. 12.71 mu g d(-1)), and transfer rate of dietary AFB(1) to milk AFM(1) (0.76 vs. 1.06%). In conclusion, the addition of BDP could be an alternative method for reducing the dietary AFB(1) bioavailability in dairy cows.