SUMMARY

Aim of this experiment was to investigate posibility of replacing inorganic form of selenium (selenite), which is present in a technology of production of mixtures for broiler feeding, with organic form of selenium (selenomethionine). Two groups of 50 chickens were formed, from which one was fed mixtures standard composition with inorganic selenium suplemented, control group, and second group of chickens fed mixtures with organic form of selenium, experimental group. In the feeding mixtures of both groups concentration of 0,3 mg/kg attained. After 42 days of experiment daily gain in control group was 42,78 g while in experimental group was 44,12 g, higher by 3,1%. Chickens of control group were weighty 1841 g. Statistical analysis not show significant differences. Control group daily consumed 80,95 g of food, and experimental group 81,88 g, so higher by 1,14 % than the control group. Food conversion ratio in the control group was 1,892 kg, and in experimental group 1,856 kg, what is less 1,93 %. From experimental results we can conclude that replacing inorganic with organic selenium have a positive effect, especially considering less toxicity of organic selenium.

          Key words: organic selenium, broilers, body weight, daily gain, consumption, conversion.