Effects of abdominal surgery on thiobarbituric acid reactive substances and plasma anti-oxidative capacity in dairy cows.

The present investigation was undertaken to study the effects of surgical stress on thiobarbituric acid reactive substances (TBARS) and ferric reducing ability of plasma (FRAP) in dairy cows. Ten Holstein-Friesian dairy cows, mean age 5.26 years, admitted for treatment of left abomasal displacement (omentopexy), were used in our study. Blood samples were collected from the jugular vein prior to surgery, immediately and then 15, 30, 60, 90 min, and 2, 5, 10, and 24 h after reposition of abomasum. Surgical stress resulted in a significant increase in plasma cortisol concentrations (P < 0.001) with the highest mean levels 15 min after surgery (32.4 +/- 18.1 microg/l) as well as in serum levels of glucose (P < 0.001) and non-esterified fatty acids (P < 0.001). Similarly, surgery transiently enhanced the plasma levels of TBARS (P < 0.001). The highest TBARS plasma levels (0.91 +/- 0.18 micromol/l) were recognized 60 min after reposition of abomasums. There were no significant differences in FRAP in dairy cows before and after reposition of abomasum. In conclusion, these data indicate that stress reaction caused by surgical correction of left displacement of abomasum can be associated with higher production of TBARS.