1. Poultry Section, Department of Production Animal Studies, Faculty of Veterinary Science, University of Pretoria, Onderstepoort 0110, South Africa
2. Klein Karoo International Research Laboratory, Oudtshoorn 6625, South Africa
3. Percy FitzPatrick Institute of African Ornithology, DST/NRF Centre of Excellence, University of Cape Town, Rondebosch, Cape Town 7701, South Africa
4. Deltamune (Pty.) Ltd., Lyttleton, Pretoria 0157, South Africa
5. Agricultural Research Council–Onderstepoort Veterinary Institute, Old Soutpan Road, Onderstepoort 0110, South Africa
6. Veterinary Services, Gauteng Department of Agriculture and Rural Development, Johannesburg 2000, South Africa
7. Deltamune (Pty.) Ltd., Oudtshoorn 6625, South Africa