[1] Northwest A&F Univ, Coll Vet Med, Minist Agr, Key Lab Anim Biotechnol, Yangling, Shaanxi, Peoples R China
[2] Northwest A&F Univ, Coll Vet Med, Dept Clin Vet Med, Yangling, Shaanxi, Peoples R China
[3] Northwest A&F Univ, Coll Vet Med, Dept Prevent Vet Med, Yangling, Shaanxi, Peoples R China