TY JOUR TI TRENDS AND PROSPECTS OF DEVELOPMENT OF MILK PRODUCTION KW milk production KW efficiency KW profitability factors JO Vestnik of Kazan State Agrarian University AU Aleksandrova, N.R. AU Subaeva, A.K. AU Mavlieva, L.. AU Titov, N.L. PY 2020 IS 15 PB Kazan state agrarian University