TY JOUR TI MODELING MILK YIELD OF CATTLE BREED WHEN CHANGING TECHNOLOGICAL PROCESSES KW farm KW process KW cattle breeding KW model KW coefficient KW productivity JO Bulletin Samara State Agricultural Academy AU Konovalov, V.V. AU Teryushkov, V.P. AU Petrova, S.S. PY 2021 IS 6 PB Samara State Agricultural Academy