Milk production functions in relation to feed inputs, cow characteristics and environmental conditions /
Heady, Earl O.(Earl Orel),1916-1986,author..
Jacobson, Norman L.,author.
Madden, J. Partick,author.
Freeman, A. E.,author.
Iowa State University.Agricultural and Home Economics Experiment Station.
Iowa State University.Department of Economics and Sociology.
Iowa State University.Department of Animal Science.
United States.Department of Agriculture.Economic Research Service.
Title from front cover.
Includes bibliographical references.