A data set from Oehlert (2000) \emph{A First Course in Design and
Analysis of Experiments}, New York: W. H. Freeman.

Data originally from Harvey F. Windels (1964) "The Influence of Diet
and of Duration of Fast upon Plasma Levels of Free Leucine, Iosleucine,
and Valine in the Growing Pig," Ph. D. thesis, University of Minnesota.

These data give the concentration of plasma free leucine
in mcg/ml 8 hours post feeding for several pigs.  The
treatments are different protein sources and percents
of protein in the meal.  Sources 1, 2, 3 are fish meal,
soybean meal, and dried skim milk.  Protein percent
levels 1, 2, 3, 4 are 9, 12, 15, and 18 percent protein.
Columns are source, percent, and response.