Comparative evaluation of antioxidant enzymes and lipid peroxidation in the milk of different ruminants

Background Milk and its products are known for their wide variety of essential nutrients such as vitamins, minerals, and biologically active substances, including antioxidants. This study aimed to compare some antioxidant enzymes and lipid peroxidation in the milk of different ruminants.Methods The ten animal species (cattle, Holstein; goats, Mahabadi; sheep, Afshari; camels, Turkman; and buffaloes, khoozestani) were randomly selected from the specified farms. Two milk samples, were collected in sterile containers from selected animals, which were clinically healthy, had the same nutrition, and were between ۳ and ۵ years old. One milk sample was used for enzymatic and lipid peroxidation assays, and the other one is prepared for somatic cell count (SCC) analysis.Results The results revealed the highest SCCs (cell/ml) in camel (۲۱۲۴۴۴.۴۴) and goat (۱۹۷۳۳۳.۳۳) milk respectively and was significantly different from other animals (P≤۰.۰۵). The highest superoxide dismutase activity was observed in sheep (۲۳۸.۰۸ U/L) and camel (۲۰۴.۴۴ U/L) milk and differed significantly from other animals (P≤۰.۰۵). In addition, Glutathione peroxidase activity was most increased in camel milk (۶۳۸.۵۶ U/L), and was statistically different from studied animals (P≤۰.۰۵). Furthermore the greatest catalase activity was detected in cattle (۱۹۱.۴۴ U/L) and goat (۱۷۴.۵۷ U/L) milk, was statistically different from other animals (P≤۰.۰۵). Besides, malondialdehyde (MDA) concentration (۸۸.۹۰μM) was highest in camel milk and significantly different from other animals (P≤۰.۰۵).Conclusion It seems that camel and fallowed sheep milk may have higher nutritional value for humans due to their higher antioxidant activity compared to the milk of other ruminants.