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A study on heifer mastitis in Japan and its causative microorganisms
National Institute of Animal Health Quarterly
|January 1, 1983
Summary
Heifer mastitis in Japan is often caused by Actinomyces pyogenes and Peptococcus indolicus, particularly in pregnant heifers during late summer. This study identifies P. indolicus in heifer mastitis for the first time in Japan.
Area of Science:
- Veterinary Medicine
- Bacteriology
- Animal Health
Background:
- Heifer mastitis is a significant concern in cattle farming.
- Previous research on heifer mastitis in Japan is limited.
- Summer mastitis in European countries shares etiological similarities.
Purpose of the Study:
- To survey and bacteriologically examine heifer mastitis cases in Hokkaido, Japan.
- To identify causative microorganisms and their associations.
- To compare the findings with European summer mastitis.
Main Methods:
- Bacteriological examination of 74 milk secretions from 67 affected heifers using the CO2 gas jet method.
- Isolation and identification of microorganisms.
- Clinical diagnosis using a milk secretion quality "score".
Main Results:
- Actinomyces pyogenes (Corynebacterium pyogenes) was isolated from 66.2% of secretions, often in mixed infections.
- Peptococcus indolicus was found in 41 secretions and frequently co-occurred with A. pyogenes.
- Streptococcus dysgalactiae was isolated from 13 secretions.
- This is the first report of P. indolicus isolation from heifer mastitis in Japan.
- The milk secretion "score" proved useful for clinical diagnosis.
Conclusions:
- The primary bacterial culprits in Hokkaido heifer mastitis are Actinomyces pyogenes and Peptococcus indolicus.
- The co-occurrence of A. pyogenes and P. indolicus is a significant finding.
- The disease in Hokkaido shares etiological similarities with European summer mastitis.
- Further research into P. indolicus's role in bovine mastitis is warranted.