Martyniuk R. Digestibility of fodder, metabolism and productive qualities of broiler-chickens for different levels of tryptophan and threonin in mixed fodders

The theoretical and experimental material of using mixed fodders with different levels of tryptophan and threonin in feeding broiler chickens of cross "Cobb-500" had been presented in the dissertation. Direction of changing in productive qualities of chickens, forage digestibility, amino acid and fat acid composition of meat and liver were indicated. The estimation of morphological and biochemical composition of blood was carried out. The morphological and chemical compound of chicken meat, amino acid composition of chest and leg muscles for different levels of amino acid feeding were investigated. Dearing broiler chickens of cross "Cobb-500" is recommended to use mixed fodder with a level of 0,21 % tryptophan for chickens from 5 to 21 days old, 0,19 % tryptophan for chickens from 22 to 35 days old and 0,16 % tryptophan for chickens from 36 to 42 days old and the level of threonin accordingly 1,00 %; 0,93 and 0,76 %.