Lipid peroxides and antioxidants in serum of neonatal calves

Objective-To examine the association between oxidative stress and antioxida nts in neonatal calves after birth. Sample Population-Sera from 6 healthy Holstein-Friesian cows and 7 of their newborn calves were obtained at various intervals after birth. Procedure-Lipid peroxides in serum of cows and their newborn calves were es timated by measuring concentrations of thiobarbituric acid-reactive substan ces (TBARS). The antioxidative activities of neonatal sera were evaluated b y measuring their superoxide-scavenging activities, ferroxidase activities, and the concentration of bilirubin-associated albumin. Results-Concentration of TEARS in neonatal sera within 1 day after birth wa s significantly higher than concentrations greater than or equal to 2 days after birth and concentrations in serum of the dams. In contrast, antioxida tive activities of neonatal sera, evaluated on the basis of super oxide-sca venging activities, ferroxidase activities, and concentration of bilirubin- associated albumin 3 hours after birth, were significantly lower than antio xidative activities in sera of the dams. Conclusions-Susceptibility of calves to oxidative stress during the neonata l period may be explained by the immature defense system against superoxide radicals.