Risk factors, isolation and drug sensitivity of microbial organism associated with sub-clinical mastitis in smallholder dairy farms in Tanga, Tanzania

Abstract

A cross-sectional study was carried between January and April 1999 in Tanga region, Tanzania to estimate the prevalence and isolate microbial agents associated with sub-clinical mastitis in smallholder dairy cows. The study also aimed at identifying risk factors associated with different management practices. A formal questionnaire sought answers on cross bred (Bos indicus x Bos Taurus) cows of varying exotic blood level and management practices. A total of 185 cows (with 738 quarters) were selected from 200 out of 3001 randomly selected smallholder dairy farms were sampled and screened for bacteriological culture growth and for elevated somatic cell counts using cow side test-California Milk Test (CMT). Overall prevalence on cows and quarters, based on bacterial growth and CMT were 61%, 22%, and 74%, 49% respectively. 29.3% of the CMT positive quarters were associated with bacterial isolate. CMT positive quarters and age were significantly associated with bacteria isolate (Odd ratio [OR] = 4.51, P <0.01, coeff. = 0.009, P = 0.001) whereas stripping milking technique (OR = 0.51, P = 0.014) seemed to be protective factor against CMT positive quarters. Staphylococcus aureus with prevalence of 24% was found to be the predominant organism.

Keywords: dairy cows, isolation, risk factors, sub-clinical mastitis, sensitivity, smallholder, Tanga, Tanzania

Bulletin of Animal Health and Production in Africa Vol. 54(1) 2006: 13-22