TY JOUR TI MEAT EFFICIENCY OF BROILER CHICKENS RECEIVING MEDECINES “PROVAGEN” AND “LACTUSAN” KW "Provagen" KW "Lactusan" KW probiotic KW prebi- otic KW chicken broilers KW meat efficiency KW meat chemical composition KW environmentally pure preparations KW live mass of a bird JO Bulletin of KSAU AU Danilova, K.A. PY 2019 IS PB Krasnoyarsk State Agrarian University