TABLE 2.
Mean percent prevalence and load of Salmonella on cull cattle hides and carcasses analyzed by season
| Salmonella parameter | Valuea
|
P value | |||
|---|---|---|---|---|---|
| Summer | Fall | Winter | Spring | ||
| Hide | |||||
| Prevalence (%) (±SD) | 93.8 ± 10.2 | 88.5 ± 13.1 | 89.8 ± 8.4 | 86.1 ± 16.9 | 0.6680b |
| Load (CFU/100 cm2) | |||||
| Enumeration positive (%) (±SD) | 17.1 ± 17.4 | 9.4 ± 10.7 | 21.3 ± 14.0 | 10.7 ± 7.5 | 0.2363b |
| n | 130 | 71 | 162 | 81 | |
| Median | 120A | 120A | 80A | 40B | <0.0001c |
| Minimum | 40 | 40 | 40 | 40 | |
| Maximum | 2.1 × 103 | 3.4 × 104 | 2.8 × 104 | 5.2 × 102 | |
| Preevisceration carcass | |||||
| Prevalence (%) (±SD) | 49.4 ± 26.3 | 51.8 ± 28.9 | 55.3 ± 31.5 | 44.2 ± 19.2 | 0.8670b |
| Load (CFU/100 cm2)d | |||||
| Enumeration positive (%) (±SD) | ND | ND | 13.0 ± 14.6 | 5.1 ± 4.4 | 0.1656e |
| n | ND | ND | 99 | 39 | |
| Median | ND | ND | 1.0 | 0.5 | 0.6536f |
| Minimum | ND | ND | 0.5 | 0.5 | |
| Maximum | ND | ND | 3.8 × 102 | 4.9 × 102 | |
| Postintervention carcass | |||||
| Prevalence (%) (±SD) | 1.3 ± 2.2 | 0.1 ± 0.4 | 0.7 ± 0.8 | 1.1 ± 2.6 | 0.5602b |
Values that do not have a common uppercase letter following them are significantly different (P < 0.05). ND, not determined.
Comparisons of mean percent prevalence or percentages of samples that were enumerable were made using a one-way ANOVA and Bonferroni's multiple comparison post-test.
Comparisons of enumeration median values were made using the Kruskal-Wallis test for nonparametric data and Dunn's multiple-comparison posttest.
Enumeration values were determined in the winter and spring sampling seasons only.
Comparisons of percentages of samples that were enumerable were made using a two-tailed unpaired t test (t = 1.463).
Comparisons of enumeration median values were made using a two-tailed Mann-Whitney U test.