This book is concerned with grain substitution by cheaper unconventional feed ingredients to formulate economic diet. Poultry farmers are facing problems in formulating ration for higher and fluctuated price of conventional and imported feed ingredients with variable quality and non availability. The problem is severe with quails as they need diet having higher protein per cent. As a part of formulating economic poultry ration replacing grains by parboiled rice polish (PRP) and different additives are going on at Bangladesh Agricultural University. PRP appears to be a good substitute of grains. Many researches were adapted to assess the nutritive value of PRP and its potentiality to replace the grains. Abundant use of PRP in lieu of grains could not provide an ideal ration for the presence of phytate. Many scientists recommended to use phytase enzyme to inactivate phytate and thus improve growth and meat yield. Feed millers, poultry farmers and others engaged with poultry operation may accept this book. This book is highlighted the concepts, definition, classification, nutritive value, chemical composition of rice polish, PRP and phytase and their effects on growth and meat yield.