FIELD: agriculture. SUBSTANCE: method involves forming a flock of poultry by the duration of embryonal development. Then, during judging or forming flocks, the random-selected male and female birds with different periods of embryonal development are subjected to stress by transferring them to a new place and keeping them it without food and water for 24 h. Meanwhile, natural resistance parameters are determined before and after stress and the birds are considered viable if their natural resistance and reaction norms are higher than those of the other birds. EFFECT: higher efficiency. 3 cl, 3 tbl
