[1] Natl Inst Vet Res, Livestock Invest Div, Vom, Nigeria
[2] Ahmadu Bello Univ, Vet Teaching Hosp, Zaria, Nigeria
[3] Ahmadu Bello Univ, Dept Vet Med, Zaria, Nigeria
[4] Ahmadu Bello Univ, Dept Vet Microbiol, Zaria, Nigeria
[5] Natl Inst Vet Res, Mol Biotechnol Div, Vom, Nigeria
[6] Natl Vet Reseasrch Inst, Bacterial Vaccine Prod Div, Vom, Nigeria