[1] Univ Liege, Lab Endocrinol & Anim Reprod, Fac Vet Med, B-4000 Liege, Belgium
[2] Univ Liege, Fac Vet Med, Clin Large Anim, B-4000 Liege, Belgium
[3] Univ Utrecht, Fac Vet Med, Dept Farm Anim Hlth, Utrecht, Netherlands
[4] Szent Istvan Univ, Fac Vet Sci, Clin Large Anim, Budapest, Hungary