Rather than a ratio of each component to the total you might consider a ratio of consumption of the feed with the larger feed level to the smaller feed level for each pen. You get a single value that is indexed by the variable 'Treatment'. Or consider the difference in consumption calculated in much the same way. That might even be better as it is much more likely to collectively have residuals that are distributed normally. The lsmeans by treatment are then a measure of how much more was consumed of the higher valued feed - which is a clear measure of preference.   SteveDenham  ... View more