The literature citation is as follows:
"Do Cows Prefer a Barn Compartment With a Grooved or Slotted Floor?" Journal of Dairy Science, J. Stefanowska, D. Swierstra, J.V. Van den Berg, and J.H. Metz, vol. 85, no. 1, January 2002, pp. 79-88.
The authors, who are at the Institute of Agricultural and Environmental Engineering, Wageningen, The Netherlands, report that:
[O]ne floor type was not clearly preferred over the other...
My winning entry was as follows:
The Dutch scholars thought it behooves
Us to find whether cows prefer grooves
To slots on barn floors,
But nature abhors
Discriminant ruminant hooves.