Johnson et al., 1997. Poult. Sci., 76 (12): 1377-1387 Document reference Johnson, M. L. ; Parsons, C. M., 1997. Effect of raw material source, ash content and assay length on protein efficiency ratio values for animal protein meals. Poult. Sci., 76 (12): 1377-1387Web http://ps.fass.org/cgi/content/abstract/76/12/1722Citation key Johnson et al., 1997Datasheets Poultry by-product meal