G. Rose - School of Veterinary and Life Sciences, Murdoch University, 90 South Street. Murdoch WA 6150, Australia
B. Paganoni - Department of Primary Industries and Regional Development, 3 Baron-Hay Court, South Perth, WA 6151, Australia
C. Macleay - Department of Primary Industries and Regional Development
C. Jones - Department of Primary Industries and Regional Development
D.J. Brown - University of New England
G. Kearney - 36 Paynes Rd, Hamilton Victoria 3300, Australia
M.B. Ferguson - AgResearch
B.E. Clarke - Murdoch University, Centre for Animal Production and Health
A.N. Thompson - Murdoch University, Centre for Animal Production and Health