There are at least two views about what is the necessary decription of a pig for the purpose of modelling it's performance on controlled feeding. On the first view the potential rate of protein retention is the only descriptor that needs to vary between kinds of pigs, with all pigs assumed to use the same rules to partition scarce resources. On the second view kinds of pigs may differ not only in their potential to grow protein but also in the rules that they use to partition a scarce resource. The purpose of the experiment reported here was to severely test the first view by using two very different kinds of pigs.