spatial hierarchical variances and age covariances for seroprevalence to leptospira interrogans serovar hardjo, bohv-1 and bvdv for cattle in the state of paraíba, brazil. | we estimated spatial hierarchal variances and age-group covariances for seroprevalence to leptospira interrogans serovar hardjo (leptoh), bovine viral-diarrhea virus (bvdv) and bovine herpesvirus type 1 (bohv-1) among 2343 cattle from 72 properties sampled in the state of paraíba, brazil in 2000. from each property, eight animals in each of the four age categories were evaluated. the age categories studied were: pre-weaned (0-6 months), young (7-18 months), replacement (19-30 months) and mature ... | 2006 | 16828906 |