[1] Univ Cambridge, Dept Pathol, Cambridge CB2 1QP, England
[2] Cent Vet Res Labs, Mol Biol & Genet, Dubai, U Arab Emirates
[3] Huazhong Agr Univ, Coll Anim Sci & Vet Med, Wuhan 430070, Peoples R China
[4] PIC Genus Plc, Abingdon OX13 5FE, Oxon, England
[5] Ralco Nutr Inc, Marshall, MN 56258 USA
[6] Univ Alberta, Dept Agr Food & Nutr Sci, Edmonton, AB T6G 2P5, Canada