Reduction of aflatoxin transfer into milk of lactating dairy cows with addition of a dietary clay adsorbent

Abstract

Twenty-four lactating Holstein cows were used in a randomized complete block design to test the efficacy of clay at reducing aflatoxin M1 (AFM1) in milk. Cows were blocked by parity and stage of lactation and were adapted to individual feed gates prior to treatment. Cows were randomly assigned 1 of 4 dietary treatments (n=6): 1) control (CON) total mixed ration (TMR); 2) aflatoxin control (AFC) TMR with 300 ppb aflatoxin B1 (AFB1); 3) adsorbent diet (CLY) TMR with 1.76 oz (50 g) of clay; 4) AFC diet with clay (CLY+AF) with 300ppb AFB1 and 1.76 oz (50 g) of clay. Data were analyzed using the GLM procedure of SAS. Main effects were treatment, days-inmilk, parity, and day. Significance was declared at P<0.05. Dry matter intake was similar across treatments; however, cows consuming CON diets had reduced milk yield. Milk from AFC cows had the greatest concentration of AFM1, and cows fed CLY+AF averaged 1.47 ± 0.186 ppb AFM1 less than cows fed AFC, resulting in a 60.0% reduction. Results from this study show that adding clay to contaminated diets was effective at reducing AFM1 concentrations in milk of cows fed AFB1 without negatively affecting production.