[1] Univ Utrecht, Fac Vet Med, Dept Farm Anim Hlth, NL-3584 CL Utrecht, Netherlands
[2] Univ Farm Anim Practice, NL-3481 LZ Harmelen, Netherlands
[3] Univ Amsterdam, Acad Ctr Dent Amsterdam, Dept Oral Biochem, NL-1081 LA Amsterdam, Netherlands
[4] Vrije Univ Amsterdam, NL-1081 LA Amsterdam, Netherlands
[5] Wageningen Univ, Business Econ Grp, NL-6706 KN Wageningen, Netherlands