Animal data frame has 20 rows and 3 columns giving the
average daily weight gains for animals with different genetic
This data frame contains the following columns:
a factor denoting the sire. (5 levels)
a factor denoting the dam. (2 levels)
a numeric vector of average daily weight gains
This appears to be a constructed data set.
Littel, R. C., Milliken, G. A., Stroup, W. W., and Wolfinger, R. D. (1996), SAS System for Mixed Models, SAS Institute (Data Set 6.4).