The Anti-Oxidative State Before and After a Diagnosed Abomasal Displacement in Cows

Objective

Abomasal displacement (DA) is one of the most important non-infection diseases in high yielding dairy cows. Aetiological factors are mainly disturbances in energy metabolism beginning in part in the dry period. Oxidative stress is involved in the pathogenesis of this disease. But there is a lack on knowledge's.

Aims

In three complexes investigations were performed to answers to the following questions: 1) Significance of antioxidants in the aetiology of abomasal displacement, 2) the antioxidative state at the time of diagnosis of DA, 3) development of antioxidative state after reposition of displaced abomasum.

Experimental design

The antioxidative state was checked in 20 healthy and 137 cows suffering from abomasal displacement: 1) 8 cows on 3rd day after parturition (ap) before DA and at the diagnosis of DA; 2) 87 cows at the diagnosis of DA; 3) 21 cows before and in the course of 24 hours after DA reposition; 4) 21 cows before as well as on first and third day after DA reposition. In the blood were analysed superoxide dismutase (SOD, erythrocyte lysate resp. serum), glutathione peroxidase (GPX, heparinized whole blood), Trolox Equivalent of Antioxidative Capacity (TEAC, serum), CK and AST (serum) as well as further haematological and clinical chemical parameters (Hitachi 704, Technicon 1).

Results

The SOD-activity increased from 6729 ± 1048 U/ml one week (w) ap to 7506 ± 1208 U/ml four w ap in erythrocyte lysate (el) of healthy cows resp. from 10 U/ml (0/50) 140 U/ml (270/340) in serum. The same trend was observable in TEAC with 226 ± 42 to 310 ± 30 μmol/l. At the second day ap were not TEAC differences between healthy and cows with later DA (237 ± 37 μmol/l) as well as at the diagnosis of DA (250 ± 74 μmol/l). Cows with DA had significant higher CK activities at second day ap (416 U/l[157/771]) and at the diagnosis of DA (313 U/l [166/414]). The SOD activity was in 87 cows at diagnosis of DA 7125 U/ml el (6154/8625) and did not differ from healthy cows. Cows with left side DA had slightly lower SOD activities than cows with right side DA. 44,8% of the cows had SOD activity <7000 U/ml el. They had higher CK and ASAT activities, bilirubin and BHB and lower cholesterol concentrations (p < 0,05). Cows with SOD activities <7000 U/ml el therefore suffered from massive metabolic stress. The GPX activity in cows with DA was 385 ± 103 U/mg Hb. Between SOD and GPX was found a negative correlation ( r = -0,40, p < 0,01). In cows with low GPX-activity the bilirubin concentrations were low, while in cows with high GPX-activities these concentrations were greatly increased. After reposition of left side DA SOD activities decreased shortly, in contrast in cows with right side for more than 24 h (p < 0.05). Cows with left side DA had higher TEAC concentrations compared with right side DA. After reposition of DA the TEAC concentration didn't differ significantly.

Conclusion

The antioxidative capacity (SOD, TEAC) increases in healthy cows after parturition. The TEAC concentration is not changed before DA, but the CK activity is higher (p < 0.05). Approximately 45% of the cows with DA have a stressed antioxidative system (SOD-activity <7000 U/ml el). This is mostly the case in cows with longer existent moderate stress, such as left side DA. Shorter and massive metabolic stress (bilirubin >17 mmol/l, glucose >8,8 mmol/l) is equivalent to GPX-activities >500 U/mg Hb. In these cases the SOD activity is only slightly decreased. The SOD activities decrease special after reposition of right side DA.