TY JOUR TI RESEARCH A SUCKING ACT OF CALVES KW calf KW sucking act KW device KW vacuum KW compression force JO Vestnik of Kazan State Agrarian University AU Zagidullin, L.R. AU Shaydullin, R.R. AU Hisamov, R.R. AU Kayumov, R.R. AU Lomakin, I.V. PY 2020 IS 14 PB Kazan state agrarian University