Authors : Molalegne Bitew, Arega Tafere and Tadele Tolosa
Abstract: Cross-sectional study was conducted on a total of 302 lactating (local and crossbred) dairy cows to determine the overall prevalence of mastitis and to isolate and identify the predominant bacterial agents involved in Bahir Dar town and its environs using Californian Mastitis Test (CMT) as screening tests. The overall mastitis prevalence recorded in the area was 85 (28.2%), out of which 9 (3%) clinical and 76 (25.2%) were subclinical cases. Of 1208 quarters examined, 23 (1.9%) were blind teats and 134 quarters (12.3%) showed evidence of infection of sub clinical mastitis. About 79 bacterial isolates were identified from CMT positive samples. Among the isolates were Coagulase Negative Staphylococci (CNS) (51.9%), Staphylococcus aureus (20.3%), Streptococcus agalactiae (8.8%), Corynebacterium bovis (0.75%) and Bacillus species (0.75%). Other species isolated include Streptococcus dysagalactiae (5.1%), Micrococcus species (3.8%), Streptococcus uberis and Actinomyces pyogenes (2.5%) each. The occurrence of mastitis varied significantly (p<0.05) between crossbred 61 (36.7%) and local Fogera 24 (17.6%). The prevalence of mastitis also significantly differed between animals with udder/or teat lesion, hygiene and parity number (p<0.05) in both breeds. There was no significant differences (p>0.05) between lactating cows with lactation stages in local Fogera breeds but it was significant (p<0.05) in crossbreds. The study showed that mastitis is the problem of dairy cows in the study area and the major isolates were contagious pathogens therefore, hygienic milking practice, culling of chronically infected cows and hygienic practices in the environment should be followed.
Molalegne Bitew, Arega Tafere and Tadele Tolosa, 2010. Study on Bovine Mastitis in Dairy Farms of Bahir Dar and its Environs. Journal of Animal and Veterinary Advances, 9: 2912-2917.