Catalase activity in milk and its correlation with milk productivity of cows depending on the duration of lactation

Relevance . The purpose of this work is to study the activity of catalase in the milk of healthy cows with different levels of productivity and to find a correlation between the studied indicators, which is important and relevant in terms of assessing the antioxidant activity of cows’ milk. Methods . The analysis of biochemical parameters of cow’s milk was carried out using the “CombiFoss 7” system (Denmark). The analysis of the total amount of water-soluble antioxidants (TAWSA) was performed on the device “Tsvet-Yauza 01-AA”. Statistical processing of the obtained results was carried out in the Microsoft Excel programs using the “Data Analysis” package, the “R” program (“Psych” package). Milk samples were obtained from black-and-white cows during a whole year. Results . The entire sample of animals (N = 280) is divided into 6 groups by lactation days: 11–30, 31–60, 61–90, 91–120, 121–180 and 180–300 days (groups 1–6). In the first 11–30 days of lactation (group 1), the value of SKVA is significantly higher (17.2 mg/ml) than in the following months. Moreover, the values of the SKVA fluctuate quite strongly. Significant changes were observed for catalase activity: from 1.41 and 1.32 rel. units (groups 1 and 6) to 0.44 rel. units (group 3). During the period of bloating and lactation decline (groups 1 and 6), the highest correlation coefficients between catalase and fat are observed — 0.51 and 0.57, respectively. For all periods of lactation, there is a negative correlation of catalase with true protein. Thus, the activity of catalase in the milk of healthy cows at different periods of lactation was studied and correlations between the studied indicators were found.