TY JOUR TI APPLICATION OF DOMESTIC BIOSTIMULANTS IN HOLSTEIN BULL FATTENING KW bulls KW Holstein breed KW biostimulant KW probiotic KW meat productivity KW slaughter quality KW carcass morphology KW meat grade. JO Agrobiotechnologies and digital farming AU Egorova, E.V. AU Simurzina, E.P. AU Semenov, V.G. PY 2026 IS 5 PB Kazan state agrarian University