TY JOUR TI PROTEIN STRUCTURE AND BIOLOGICAL VALUE OF SPRING BARLEY GRAINS FOR FEED PURPOSES KW spring barley (Hordeum vulgare L.) KW variety KW biological value KW ranking KW crude protein KW essential amino acids KW pigs JO Vestnik of Kazan State Agrarian University AU Blokhin, V.. AU Nikiforova, I.Y. AU Kadyrova, F.Z. AU Lanochkina, M.. AU Malafeeva, Y.. PY 2026 IS 20 PB Kazan state agrarian University