Table 2

Results of bacteriological cultures of milk samples of a) 104 quarters (66 cows) with a California Mastitis Test ≥ 4 at the initial udder health examination of 257 cows; b) 38 cases of clinical mastitis yielding 42 sampled quarters (one harboured two pathogens); and c) 107 udder quarters in 27 cows with UDS1 ≥ 4 at drying off (one cow had a blinded quarter)


Initial examination
Clinical mastitis2
Drying off2

Culture results
N
%
N
%
N
%

Staphylococcus aureus (of which β-lactamase prod.)
19 (2)
18.3 (10)
5 (1)
11.9 (20)
7 (0)
6.5 (0)
Coagulase negative staphylococci (of which β-lactamase prod.)
17 (5)
16.4 (30)
0
0.0
7 (3)
6.5 (43)
Streptococcus uberis
8
7.7
3
7.0
5
4.7
Streptococcus dysgalactiae
10
9.6
4
9.3
2
1.9
Escherichia coli


8
18.6


Arcanobacterium pyogenes


1
2.3


Mixed growth
10
9.6
1
2.4


Negative
40
38.5
21
50.0
86
80.0

1 Udder disease score (UDS) are graded 0–9, where each figure indicates a 10% increase of the probability that the cow has infectious mastitis.

2 Samples taken by farmers using Mastistrip®.

Hamilton et al. Acta Veterinaria Scandinavica 2006 48:11   doi:10.1186/1751-0147-48-11