LAUSR

The aim of this study was to evaluate the concentrations of total (T-GSH), oxidized (GSSG) and reduced glutathione (GSH) in blood of clinically healthy calves, to assess the effect of sex and age together with the type of feeding on its concentrations, and to assess the relationships between glutathione and metabolic indices. A total of 117 Holstein calves at the age of 1 day to 6 months were divided according to age and together with the type of feeding into 4 groups: colostrum and transition milk (n = 20), native milk (n = 39), milk replacer (n = 29) and total mixed ration (n = 29). Blood serum was used for the assessment of the metabolic profile of calves. The concentrations of individual forms of glutathione (mean ± SEM) were as follows: T-GSH: 789.1 ± 19.4 µmol/l, GSSG: 54.2 ± 4.3 µmol/l, GSH: 681.6 ± 15.3 µmol/l, and GSH/GSSG: 41.1 ± 5.9, with the coefficients of variability of 26.6%, 85.3%, 24.3% and 157.4%, respectively. Age and the type of feeding affected GSSG (P≤ 0.01) and GSH/GSSG (P≤ 0.01). The relationships between glutathione and biochemical parameters were mostly weak. T-GSH correlated with creatinine (P≤ 0.05) and chlorides (P≤ 0.05); GSSG correlated with albumin (P≤ 0.01), creatinine (P≤ 0.01), cholesterol (P≤ 0.05), aspartate aminotransferase (P≤ 0.01), alanine aminotransferase (P≤ 0.01), gamma-glutamyltransferase (P≤ 0.05) and calcium (P≤ 0.05); GSH/GSSG ratio correlated with creatinine (P≤ 0.01), cholesterol (P≤ 0.05), aspartate aminotransferase (P≤ 0.05), gamma-glutamyltransferase (P≤ 0.01) and calcium (P≤ 0.05). The evaluation of individual forms of glutathione helps in estimation of redox status in healthy animals and their monitoring can detect the stress extent.