The aim of the research was to determine values of selected parameters of protein metabolism and enzyme activities in blood serum of female polar foxes of different ages after the post-reproduction and post-lactation recovery period. During the experiment, 50 healthy fox vixens from a domestic breeding farm were examined. The animals were divided into 5 age groups (n = 10), from 1 until 5-years-of-age. In blood serum samples total protein, protein fractions, urea and creatinine concentration were determined along with the activities of the enzymes: aspartate aminotransferase (AST), alanine aminotransferase (ALT) and lactate dehydrogenase (LDH). There were no statistically significant age-dependent differences among biochemical parameters values in the blood of the experimental animals. The only thing noted was a tendency of an increased total protein level in the vixen’s blood with age and following the reproduction season.
The study was carried out on 50 female polar foxes, which were divided into 5 experimental groups with respect to age (n - 10): from 1 to 5-years-of-age. The content of triglycerides, total cholesterol, HDL, LDL, total, free and estrified L-carnitine and the composition of fatty acids was determined in blood serum samples. The lowest content of triglycerides, total cholesterol and HDL fraction was found in one-year-old females (p < 0.05). It was observed that there was a tendency towards an increase in the content of triglycerides and LDL until 3-years-of-age and in total cholesterol and HDL until 4-years-of age. No significant, age-dependant changes in the content of individual fatty acids and L-carnitine were observed. Among fatty acids, the dominant ones were C16:0; C18:0; C16:1; C18:1 and n-6 PUFA, where C16:2 n-6 prevailed.