| Mastitis causing bacteria
Contagious mastitis
- - primary source: udders of infected cows,
- - is spread to other cows primarily at milking time,
- - results in high bulk tank SCC.
It is caused by:
- Streptococcus agalactiae (> 40% of all infections),
- Staphylococcus aureus (30 - 40% of all infections).
The S. aureus bacterium is hardly eradicable, but can be reduced to less than 5% of the cows in a herd. The S. agalactiae is fully eradicable from a herd.
Environmental mastitis
- Primary source: the environment of the cow.
- High rate of clinical mastitis (especially the lower resistant cows, e.g. Early lactation).
- Individual scc is not necessarily high (less than 300,000 is possible) .
It is caused by:
- environmental steptococci (5 - 10% of all infections).
- Streptococcus uberis.
- Streptococcus bovis.
- Streptococcus dysgalactiae.
- Enterococcus faecium.
- Enterococcus faecalis.
- - Coliforms (< 1% of all infections):
- Escherichia coli.
- Klebsiella pneumoniae.
- Klebsiella oxytoca.
|
