Role of learning in the selection of dietary protein in the golden hamster (Mesocricetus auratus).

Hamsters (Mesocricetus auratus) were kept for several weeks on maintenance diets (MDs) that were either nutritionally complete or protein deficient, and had periodic access to protein-free and high-protein conditioning diets (CDs) with marker flavors (anise and clove). In Experiment 1, protein-restricted hamsters came to prefer the flavor of high-protein CDs but did not prefer unflavored high-protein CD. Thus, hamsters learned to select dietary protein by attending to the flavor of the CD. In Experiment 2, a within-subjects design was used, and MDs also had marker flavors (garlic and sage). Hamsters came to prefer the flavor of high-protein CD when protein restricted, and they showed this preference even in the absence of protein restriction if reexposed for only 90 min to merely the flavor of a protein-deficient MD. Thus, learned associations between the flavor and the usual postingestional consequences of a recently ingested MD can affect short-term dietary protein selection.