Did you know that cows might be more selective in their eating habits than goats? To explore this question, Carl Linnaeus gathered a collection of 643 distinct plant species, which were then given to horses, cows, pigs, sheep, and goats to eat. Although the findings were meticulously compiled, they remained unexamined until now, 275 years later, when the results are also being published by the Linnean Society in London.
“This could be regarded as a pioneering experiment in the field of ecology, which really gained traction in the late 19th century. By current standards, it was a significant study with an impressive array of plant species involved,” remarks Håkan Rydin, a Professor of Plant Ecology at Uppsala University and one of the researchers leading the analysis.
Carl Linnaeus’ thesis, titled Pan Svecicus, outlines 2,325 experiments conducted with 643 different plant species. The thesis was published in 1749 and presented by his student, Nils Hesselgren. Prior to this, Linnaeus and his students traveled throughout Sweden, gathering insights from farmers about the best grazing grounds for their livestock.
Despite being translated into both German and English and gaining recognition among botanists across Europe, the outcomes of Linnaeus’ thesis had never been analyzed until now. Rydin, along with a team of researchers, has finally undertaken the task of compiling and examining the data.
The findings reveal that pigs were the least selective, consuming only 32% of the 204 plant species tested on the animals. Following them were horses, who ate 59%, cows at 66%, sheep at 82%, and goats at 85%. Overall, the animals showed a preference for legumes and grasses.
“Pigs are likely the fussiest eaters because they have an omnivorous diet, unlike other animals that mainly eat plants. Interestingly, the animals were not very adept at steering clear of toxic plants; however, cows and horses excelled in that area,” Rydin clarifies.
The thesis includes various data points and references to Flora Svecica, Linnaeus’ catalog of Swedish plants. The researchers believe this was one of the initial instances where Linnaeus employed a naming convention that is now widely used, which has enabled them to identify the plant species involved in these experiments.
“Carl Linnaeus established the foundation for later scientists to delve into this research area. It wasn’t until about 200 years later that biologists began applying statistical methods. What is truly remarkable is that all the data was documented. In more recent studies, it is likely that researchers would not have preserved the raw data,” concludes Rydin.
