Redox status during pregnancy, peri-parturition and post calving-first insemination period in ferisian cows

الملخص EN

A total of fifteen late pregnant Holstein Friesian cows with different parities were selected 3-6 weeks before calving.

231 Jugular Blood samples were collected weekly along 18 weeks for serum separation.

Serum Hydrogen peroxide H2O2), Malondialdehyde (MDA) and Total antioxidant capacity (TAC) were measured colorimetrically.

Both H2O2 and MDA averages were increased gradually and reached the peak(P<0.01) one week before calving, TAC averages were dropped at the 5th week and increased gradually to peak again at the last week before calving and fluctuated with a peak (P<0.01) at the 10th week post- calving.

The Parity and cow effect was significant for (H2O2& MDA) and TAC averages, P<0.05 and p<0.01 respectively.

Cows having retained placenta were accompanied by high H2O2 (323.9± 19.69 μmol/L) and low serum TAC (1790.8 ± 12.32 mmol/L) concentration, (P<0.01).

Cows not bred after calving showed high (P<0.01) H2O2 (292.6 ± 11.46 μmol/L) and low TAC averages (1890.1± 17.33 mmol/L) comparing to cows that bred either became pregnant or not.

The study declared that the addition of antioxidant to the ration or the injection of vitamin E may play a role to overcome the redox status of the cows under investigation