Activities of N-acetyl-β-d-glucosaminidase and glutathione peroxidase in bovine colostrum and milk

Abstract

Parturition and post partum period are susceptible for antioxidative/oxidative imbalance as well as inflammatory processes related to either uterus or mammary gland. Fifteen Holstein-Friesian cows were used to examine the relationship between the antioxidant enzyme glutathione peroxidase (GSH-Px) and inflammatory enzyme N-acetyl-glucosaminidase (NAGase) in colostrum and milk during 12 days after parturition. Samples from each udder quarter were collected immediately after parturition, after 24 h and 48 h as well as after 6 and 12 days post partum. The activity of GSH-Px was measured spectrophotometrically and NAGase spectrofluorimetrically. NAGase activity generally remained constant during the examined period confirming no inflammation and healthy udder. Moreover, no significant differences in the activity among quarters were detected. The activity of GSH-Px rose significantly (P < 0.05) in the examined period suggesting the dynamic balance of antioxidative defence. No differences among quarters confirmed that in healthy quarters metabolic processes are on a similar level but positive correlations between the antioxidative and inflammatory enzyme in quarters and with regard to time may suggest a possible relationship during inflammation.