TY JOUR TI PHENOTYPIC EFFECTS OF SOMATOTROPONOGO CASCADE GENES ASSOCIATED WITH BEEF PRODUCTIVITY OF KAZAKH WHITE-HEADED BREED COWS KW genes KW cascade KW polymorphism KW productivity KW breed KW somatotropic KW beef JO Bulletin Samara State Agricultural Academy AU Beishova, I.S. PY 2018 IS PB Samara State Agrarian University