Table 4.
Associations between somatic cell counts (SCC x1000/ml) and intramammary infection (IMI) in udder quarter milk samples taken from beef cows within a month after calving and at weaning in 10 beef cow herds
|
Bacterial findings |
After calving |
At weaning |
||||
|---|---|---|---|---|---|---|
| Median SCC (50% central range) | n | P-value | Median SCC (50% central range) | n | P-value | |
| IMI |
|
|
|
|
|
|
| No |
48 (22–104) |
314 |
|
44 (13–188) |
295 |
|
| Yes |
346 (75–1113) |
50 |
<0.0001 |
303 (58–1041) |
56 |
<0.0001 |
| IMI, not CNSa |
|
|
|
|
|
|
| No |
48 (22–104) |
312 |
|
44 (13–188) |
295 |
|
| Yes |
820 (185–2605) |
24 |
<0.0001 |
370 (75–1946) |
29 |
<0.0001 |
| IMI |
|
|
|
|
|
|
| No |
48 (22–104) |
314 |
|
44 (13–188) |
295 |
|
| CNSa |
106 (66–425) |
26 |
|
218 (30–802) |
27 |
|
|
S. aureus |
820 (185–2487) |
20 |
|
419 (97–2318) |
21 |
|
| Other | 1782 (353–3208) | 4 | <0.0001b | 239 (37–677) | 8 | <0.0001c |
aCNS = coagulase negative staphylococci.
bCNS, Staphylococcus aureus and other pathogens (only Streptococcus dysgalactiae) had significantly higher SCC than no IMI; S. aureus and other pathogens had significantly higher SCC than CNS.
cCNS and S. aureus had significantly higher SCC than no IMI; S. aureus had significantly higher SCC than CNS and other pathogens (2 Escherichia coli, 1 Serratia marcescens, 1 Str. dysgalactiae, 1 Str. uberis and 3 coagulase positive staphylococci (not S. aureus).