[1] Univ Padua, Dept Anim Med Prod & Hlth, Viale Univ 16, I-35020 Legnaro, Italy
[2] Melbourne Vet Sch, Fac Sci, Dept Biomed Sci, Melbourne, Vic, Australia
[3] Univ Pretoria, Fac Vet Sci, Dept Prod Anim Studies, Onderstepoort, Pretoria, South Africa
[4] Oregon State Univ, Dept Anim & Rangeland Sci, 112 Withycombe Hall, Corvallis, OR 97331 USA
[5] Tufts Univ, Cummings Sch Vet Med, Dept Vet Clin Sci, North Grafton, MA 01536 USA
[6] Vetmeduni Vienna, Ctr Reprod, Vet pl 1, A-1210 Vienna, Austria