Are cows pickier than goats? Linnaeus’s innovative large-scale feeding experiment

Abstract In 1749, Linnaeus published Pan Svecicus, a thesis that was defended by his student Nils Hesselgren. The thesis describes food preference trials in cows, goats, sheep, horses, and pigs, and includes 2325 tests with 643 plant species. The data had surprisingly little bearing on the text in the thesis, and even though the experiments quickly became internationally known, the data were merely repeated, rather than discussed. We have digitized the data and linked the species names to modern nomenclature and present the first analysis and discussion of the results. Pigs were most selective (eating 32% of the 204 plant species that were tested on all animals), followed by horses (59%), cows (66%), sheep (82%), and goats (85%). The ruminants (especially goats and sheep) had high overlap in food choice, and the pigs deviated most (despite the fact that pigs are more closely related to the ruminants than are horses). Among plant orders, Fabales and Poales were generally preferred, while Lamiales and Ranunculales were avoided, especially by cows and horses. Cows and horses were also more keen to avoid toxic plant species. All animals showed a preference for species that are today considered nutritious. We now make the data available, for further analyses in ecology, history of science, and other disciplines.