Twenty-four Holstein cows were randomly allocated to four equal experimental groups containing a control (n = 6) and three treatment (n = 6) groups. Experimental animals were selected according to their average milk yield, weight, and body condition score. The experimental groups received basal diet + Saccharomyces Cerevisiae cell wall (SCW) (group 1), basal diet + bentonite + SCW(group 2), basal diet + bentonite (group 3), and basal diet (control), on a dry matter basis (group 4). Blood samples were taken 4, 3, and 1 week prior to and 1 and 3 weeks following parturition. Serum concentrations of haptoglobin (Hp), serum amyloid A (SAA), lipopolysaccharide (LPS), and concentration of aflatoxin B1 in ration and M1 in milk and blood were determined during the transition period. The results showed that LPS concentration in blood was in the normal range in all groups. The acute-phase proteins (Hp and SAA) were in the normal range as well. The concentration of aflatoxin M1 in the serum of the control group was higher than other groups, yet lower in the group receiving toxin binders (p < 0.05). The mean aflatoxin M1 concentration in milk was the lowest in the group receiving SCW(p < 0.05). Similarly, the concentration of aflatoxin M1 in milk was the highest in the control group (p < 0.05). The study also showed that the levels of endotoxin in ration of different groups resulted from our experimental diet were not high enough to stimulate APP response. It was further observed that SCW might be able to reduce the level of aflatoxin in serum and milk. The results obtained from our study may lead to a better understanding of using dietary supplements, such as bentonite and yeast cell wall, during the transitional period. Moreover, the studymay contribute to our knowledge on simultaneous LPS and toxin binders for providing more safe food during the transition period in cattle.

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