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THE NEW SOUTH WALES MASTITIS CONTROL PROGRAM
Author(s) -
Mylrea P. J.,
Hoare R. J. T.,
Colquhoun Patricia,
Links I. J.,
Barton R. J. Richards Mary
Publication year - 1977
Publication title -
australian veterinary journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.382
H-Index - 59
eISSN - 1751-0813
pISSN - 0005-0423
DOI - 10.1111/j.1751-0813.1977.tb07938.x
Subject(s) - herd , mastitis , streptococcus agalactiae , veterinary medicine , penicillin , biology , zoology , streptococcus dysgalactiae , medicine , antibiotics , microbiology and biotechnology , streptococcus , bacteria , genetics
SUMMARY Bacteriological examinations were made on quarter samples from cows in 35 herds over a 3 year period to monitor the response in a mastitis control program. Initially, Staphylococcus aureus predominated in 32 of the herds and the mean herd prevalence was 26%. The control measures halved this rate but there was considerable variation in response between herds. The decline occurred rapidly and there was a significant reduction ( P < 0.01) by 3 months. Streptococcus agalactiae predominated in 3 herds and the overall infection rate was 4.9%. Control measures eliminated the infection completely from most herds but re‐infection occurred in 2 herds. The greatest decline occurred in the first 6 months and was significant (P < 0.05). The measures had little effect upon Str. uberis and Str. dysgalactiae which remained fairly consistently at low levels. Initially, strains of Staph. aureus resistant to penicillin were dominant in most herds. In a minority of herds strains resistant to streptomycin predominated and in these herds there was a concurrent resistance to penicillin. These patterns did not change greatly over the control period. Resistance by Str. agalactiae to streptomycin occurred in most herds at the start of the program.