Results

- Markers of Oxidative Status in Plasma and Erythrocytes of Transition Dairy Cows During Hot Season

 
Climatic Conditions and Clinical Parameters

During spring, mean daily values of THI were 58.5 ± 3.7during the daytime (from 0900 to 2000 h), and 53.3 ±4.0 during the nighttime (from 2100 to 0800 h). In summer, meandaily values of THI were equal to 75.2 ± 2.6 during thedaytime, and to 71.2 ± 2.5 during the nighttime (Figure1).

Values of RT differed significantly between SU and SP cows (39.5vs. 39.1°C, P P

Plasma concentration of TBARS (Table 2) and concentration ofSHp and activity of GSH-Px-P did not significantly differ betweenSU and SP cows (Figure 2). Lower (P

Erythrocyte TBARS, SOD, and SH were higher (P ranging from P P

Evolution of plasma and erythrocyte markers of the oxidativestatus during the transition period were similar between thetwo groups of cows (Tables 2 and 3, Figure 2): activity of SOD,GSH-Px-P, and GSH-Px-E and concentrations of SHp and SH peakedaround calving (between -3 and +1 d from calving). Mean valuesafter calving did not differ from those registered before calving,however. Plasma concentrations of ROM and TBARS tended to increasepostpartum, showing higher values (P