Protein efficiency ratio: AACC/ASTM collaborative study
Hackler, L.R.; Bodwell, C.E.; Happich, M.L.; Phillips, J.G.; Derse, P.H.; Elliott, J.G.; Hartnagel, R.E.; Hopkins, D.T.; Kapiszka, E.L.; Mitchell, G.V.
Journal - Association of Official Analytical Chemists 67(1): 66-77
1984
ISSN/ISBN: 0004-5756 PMID: 6698933 Document Number: 225523
8 laboratories (7 of the laboratories conducted animal experiments) participated in a collaborative study to standardize some of the methodology associated with animal bioassays for determining protein efficiency ratios and to suggest improvements which would reduce the variation among laboratories. 1-, 2-, 3- and 4-wk protein efficiency ratios (PER) with 0-, 2- or 4-day adaptation periods were obtained from each laboratory, resp., for 6 protein sources: casein, lean beef, lactalbumin, textured vegetable protein, groundnut flour and wheat flour. Analyses were computed for PER and adjusted PER (APER). From the analysis of variance for PER and APER, significant (P less than 0.05) effects were observed due to laboratories, adaptation length, protein sources, and/or interactions among these variables. In general, APER values show much less variation among laboratories than PER values. The reproducibility and repeatability variances were significantly (P less than 0.05) greater for an assay length of 2 wk than they were for 3- or 4-wk assays. Two protein sources, casein and textured vegetable protein, were fed at both high (10%) and low (6%)levels. Analysis of variance of PER values shows a significant (P less than 0.05) laboratory by protein level by assay length interaction.