Effect of various forms and levels of selenium on milk productivity and resistance of lactating cows

Abstract

The effect of two forms of selenium, inorganic and organic, was evaluated in the study. Lactating cows of the 1st control group were fed 4.9 mg/head/day of inorganic form of selenium, cows of the 2nd, 3rd and 4th experimental groups received organic form of selenium in the amounts of 2.5, 3.7 and 4.9 mg/head/day. Researches show that application of organic form of selenium permits to increase average daily milk yield by 3.3, 12.9 and 10.8% (р < 0.05), while increasing of dry matter concentration in milk by 0.57% (р < 0.05) in comparison with the 1st control group. When administering selenium in organic form 3.7 mg/head/day, there was a tendency to increase in amount of casein and decrease in amount of somatic cells in milk by 0.13% and 33.7 thousand/ cm3 respectively (р < 0.1). A dose of 4.9 mg/head/day of organic selenium contributed to a decrease in amount of somatic cells by 29.3 thousand/cm3 (р < 0.05). Feeding experimental groups with organic form of selenium in different doses had a positive effect on the immune status and antioxidant activity of blood serum. The content of free water-soluble antioxidants (TAWSA) in blood serum was higher by 39.3 and 53.5% (р < 0.001) in cows of the 3rd and 4th experimental groups fed 3.7 and 4.9 mg/head/day of organic selenium. Thus, the use of selenium in organic form is the most effective and allows to reduce the amount of used micronutrient for replenishment of animal needs.