The effect of selenium on the level of glutathione in the blood of young farm poultry of meat production direction

Selenium is an indispensable biotic trace element that takes an important role in the antioxidant protection of the body's cell components from the destructive effects of various oxidants. Selenium is able to increase the biological activity of both enzymatic and non-enzymatic antioxidant systems of the body. Thiols occupy a special place among antioxidants, the functioning of which is mainly provided by the glutathione system. Glutathione, as the main intracellular thiol, plays an important role in metabolic and physiological processes occurring in living organisms: synthesis and degradation of proteins and DNA, activation and inactivation of enzymes, synthesis of prostaglandins and deoxyribose metabolites, stabilization of cell membranes, transport of amino acids, etc. It can function in the body both as a reducing agent and as a nucleophilic center, which is important for ensuring redox homeostasis in the body. The aim of the research was to study the effect of selenium supplements in compound feed on the level of glutathione in the blood of young meat poultry of various types of farm poultry. The research were conducted on broiler chickens of the Сobb 500 cross, goslings of the Gorky breed and ducklings of the Ukrainian white breed. Four groups were formed from day-old chickens, goslings and ducklings (one control and three experimental). Poultry of the experimental groups were additionally introduced into compound feed with different amounts of selenium (from 0.2 to 0.6 mg/kg) according to the experimental schemes. Sodium selenite was used as a source of selenium. Blood samples from experimental poultry were taken at the end of the growing period (at the age of 42, 75 and 56 days, respectively). The concentration of different forms of glutathione in the blood was determined by the iodometric method. It has been established that feeding broiler chickens, goslings and ducks with Selenium-enriched feed during the growing period promotes the activation of the glutathione link of the non-enzymatic antioxidant defense system of the body, as evidenced by an increase in the concentration of total glutathione in the blood (by 2.5–9.9 %) and its reduced form (by 2.5–11.7 %). The level of glutathione concentration and its forms in the blood of young farm poultry depended on several factors: firstly the type of poultry (the highest in young ducks, the lowest in broiler chickens, goslings occupied an intermediate position); secondly the dose of Selenium introduction into feed (low (0.2 mg/kg) and high (0.6 mg/kg) doses had a smaller positive effect on the level of glutathione); thirdly individual characteristics of the poultry (a significant range of values (lim) of indicators was noted in the groups).