Table 1.
Salmonella Percent (%) Prevalence, and Standard Error (SE) in Subiliac Lymph Nodes (LNs) of Fed and Cull Cattle at Harvest, by Region and Season
| |
Cull cattle subiliac lymph nodesa |
|
Fed cattle subiliac lymph nodesa |
|
||||
|---|---|---|---|---|---|---|---|---|
| Sample period | Region 2 | Region 3 | Region 5 | All Cull | Region 3 | Region 5 | All Fed | Overall by season |
| Fall 2010 | ||||||||
| Sample sets collectedb | 2 | 4 | 2 | 8 | 4 | 2 | 6 | 14 |
| Number LNs tested | 152 | 304 | 152 | 608 | 279 | 152 | 431 | 1039 |
| Mean % (SE) | 0.65 (0.65) | 0.97 (0.62) | 0 | 0.65 (0.35) | 29.6 (1.5) | 0 | 19.7EF (6.3) | 8.8 (3.7) |
| Median % | 0.65 | 0.65 | 0 | 0D | 28.3 | 0 | 27.6 | 0.65 |
| Minimum % | 0 | 0 | 0 | 0 | 27.6 | 0 | 0 | 0 |
| Maximum % | 1.3 | 2.6 | 0 | 2.6 | 34.1 | 0 | 34.1 | 34.1 |
| Winter/Spring 2011 | ||||||||
| Sample sets collectedb | 2 | 4 | 2 | 8 | 4 | 2 | 6 | 14 |
| Number LNs tested | 151 | 305 | 152 | 608 | 305 | 147 | 452 | 1060 |
| Mean % (SE) | 3.3 (0.7) | 0.32 (0.32) | 0 | 0.98 (0.54) | 2.3 (0.34) | 0.7 (0.7) | 1.8E (0.44) | 1.3 (0.37) |
| Median % | 3.3 | 0 | 0 | 0D | 2.6 | 0.7 | 1.9 | 1.3 |
| Minimum % | 2.6 | 0 | 0 | 0 | 1.3 | 0 | 0 | 0 |
| Maximum % | 4.0 | 1.3 | 0 | 4 | 2.8 | 1.4 | 2.8 | 4.0 |
| Summer/Fall 2011 | ||||||||
| Sample sets collectedb | 2 | 4 | 2 | 8 | 6 | 2 | 8 | 16 |
| Number LNs tested | 152 | 306 | 152 | 610 | 466 | 152 | 618 | 1228 |
| Mean % (SE) | 1.3 (0) | 0.65 (0.38) | 12.5 (8.6) | 3.8 (2.5) | 24.7 (8.0) | 13.2 (1.4) | 21.4F (5.9) | 12.0 (3.8) |
| Median % | 1.3 | 0.65 | 12.5 | 1.3D | 20.0 | 13.2 | 17.7 | 3.9 |
| Minimum % | 1.3 | 0 | 3.9 | 0 | 1.3 | 11.8 | 1.3 | 0 |
| Maximum % | 1.3 | 1.3 | 21.1 | 21.1 | 47.4 | 14.5 | 47.4 | 47.4 |
| Overall by region or type | Lymph nodes overall | |||||||
| Sample sets collectedb | 6 | 12 | 6 | 24 | 14 | 6 | 20 | 44 |
| Number LNs tested | 455 | 915 | 456 | 1826 | 1050 | 451 | 1501 | 3327 |
| Mean % (SE) | 1.75 (0.56) | 0.65 (0.25) | 4.2 (3.4) | 1.8 (0.88) | 19.3 (4.4) | 4.6 (2.7) | 14.7 (3.5) | 7.5 (1.9) |
| Median % | 1.3A | 0A | 0A | 0.65G | 20.0B | 0.7C | 11.8H | 1.3 |
| Minimum % | 0 | 0 | 0 | 0 | 1.3 | 0 | 0 | 0 |
| Maximum % | 4.0 | 2.6 | 21.1 | 21.1 | 47.4 | 14.5 | 47.4 | 47.4 |
Common uppercase superscripts indicate values that are not significantly different (p>0.05).
Approximately 76 LNs collected per set, two sets collected per plant, approximately 1 month apart in each season.
Median cull cattle prevalence by region was not significantly different (p=0.2356) one-way analysis of variance (ANOVA) Kruskal–Wallis nonparametric test; Dunn's multiple comparison post-test.
Median fed cattle prevalence by region was significantly different (p=0.0198) Mann–Whitney nonparametric two-tailed t-test.
Median cull cattle prevalence by season was not significantly different (p=0.3007) one-way ANOVA Kruskal–Wallis nonparametric test; Dunn's multiple comparison post-test.
Mean fed cattle prevalence by season was significantly different (p=0.0304) one-way ANOVA and Bonferroni's post-test.
Median lymph node prevalence overall for cull and fed cattle was significantly different (p=0.0006) Mann–Whitney nonparametric two-tailed t-test.