author(s)
Ali Kadhem Hamza and Wasan A Gharbi

abstract
The present study was conducted to investigate the effect of selenium toxicity on some blood, cellular and biochemical parameters in adult Awasiy ewes. The first group (DW) included ten ewes pumped with distilled water daily for ten weeks, the second group (SS+RX) included ten ewes pumped with salt sodium selenite (1.2 mg / kg BW) daily and orally for eight weeks and then treated with N-Acetyl L-cysteine (70 mg / kg BW) daily and orally from week 9 to week 10. The third group (SS) also included ten ewes that were injected with sodium selenite (1.2 mg / kg BW) orally daily for 10 weeks. The results of this study also showed a significant increase (P0.05) in the second group (SS+RX) and SS (SS), which was injected with sodium selenite on serum selenium concentration starting from the first week to At the end of the experiment, selenium concentration showed a decrease starting from the ninth week in the second group (SS+RX) after treatment with N-Acetyl L-cysteine until the end of the experiment compared with the control group. The results of these study also showed a significant (P≤0.05) increase of glutathione peroxidase concentration in groups (G2, G3) start in week one (W1) till the fifth week which reach the peak, then its start to decline and continue until the end of experiment in (G3), while it was returned to normal level in the ninth week and remain steady until the end of the experiment in (G2) compared with control group. The cellular tests performed on the blood lymphocytes included chromosomal aberration, which showed significant results of P0.05 in the two groups that were injected with sodium selenite, the second group (SS+RX) and (SS) compared to the control group (DW). These abnormalities began from the end of the first week of the experiment until the end of the tenth week in both groups even after treatment with N-Acetyl L-cysteine for the second group (RX + SS) which starts from the ninth week until the end of the tenth week. The second cytological examination included micronucleus, which showed a significant change (P0.05) in both the (SS+RX) and (SS) and the (SS) compared to the control group (DW), which began from the end of the third week until the end (N-Acetyl L-cysteine) in the second group (RX + SS), starting from the ninth week and ending with the experiment. The current study indicates that changes in the genetic level of the cells remain constant despite the given treatment and the return of cases to normal bed and laboratory, which confirms that the poisoning of the element of selenium is dangerous and permanent effects.