This study used 320 Holstein cows in the breeding season at the postpartum period, which began four weeks before breeding and ended with a pregnancy confirmation examination. Cows were divided into four groups that provided a total mixed ration (TMR) but differed in the source of corn silage formulated according to (NRC2001). Group 1 (G1) fed good corn silage with 10 gm of Calibrin-Z/head (Montmorillonite clay). Group 2 (G2) and group 3 (G3) fed corn silage contaminated with Zearalenone and supplied with (10, 60) gm Calibrin-Z/head, respectively, while group 4 (G4) fed the same contaminated silage and supplied with 20 gm Glucomannan/head (Yeast stimulate, Saccharomyces Cerevisiae Cell Wall). TMR, feed stuff and corn silage were tested for mycotoxins (Aflatoxins, Zearalenone). Milk production, feed consumption, and reproductive performance were monitored. Samples of blood were drawn from 10 cows for each group for examination of oxidative indices, some blood biochemical and immunological parameters, and to monitor DNA integrity. The results showed that (G4) showed a significantly higher reproductive response than (G3). Aspartate Aminotransferase significantly decrease in (G3) and (G4) compared with (G2), significant increase in catalase activity in (G3) compared with others groups. Also, nitric oxide (NO) and lymphocyte transformation increased significantly in (G4) compared with (G3). The DNA integrity of whole blood was significantly lower in (G 3) and (G 4) compared with (G 2).