Table 1.
Morbidity and mortality data summary by pen persistent infection status in a study to investigate the effect of bovine viral diarrhea virus (BVDV) infections on the overall health and performance of feedlot cattle
| Pen persistent infection status
|
|||||
|---|---|---|---|---|---|
| Variable | PI pensf | Non-PI pensg | Relative riskh | 95% CIi | P-value |
| Number of pens | 9 | 16 | |||
| Number of animals | 2504 | 4628 | |||
| Initial UF treatmenta,j (%) | 11.64 | 10.99 | 1.06 | 0.75–1.49 | 0.742 |
| Initial NF treatmenta,j (%) | 7.03 | 9.07 | 0.77 | 0.52–1.15 | 0.201 |
| Overall mortalityj (%) | 2.22 | 2.83 | 0.79 | 0.55–1.12 | 0.179 |
| Infectious mortalityj (%) | 1.28 | 1.98 | 0.65 | 0.40–1.06 | 0.082 |
| BRD mortalityb,j (%) | 0.64 | 1.07 | 0.60 | 0.31–1.14 | 0.115 |
| HS mortalityc,j (%) | 0.54 | 0.76 | 0.72 | 0.39–1.33 | 0.288 |
| AR mortalityd,j (%) | 0.07 | 0.11 | 0.62 | 0.15–2.59 | 0.517 |
| BVDV/Enteritis mortalitye,j (%) | 0.24 | 0.03 | 7.92 | 1.01–62.43 | 0.049 |
| Metabolic mortalityj (%) | 0.30 | 0.28 | 1.07 | 0.54–2.10 | 0.854 |
| Miscellaneous mortalityj (%) | 0.44 | 0.50 | 0.89 | 0.49–1.62 | 0.699 |
UF — undifferentiated fever; NF — no fever
BRD — mortality caused by bovine respiratory disease
HS — mortality caused by Histophilus somni disease
AR — mortality caused by arthritis
BVDV/Enteritis — mortality caused by bovine viral diarrhea virus and/or other infections of the gastrointestinal tract
PI Pens includes pens that had at least 1 animal with a BVDV persistent infection (PI)
Non-PI Pens includes pens that did not have an animal with a BVDV PI
Relative Risk is the ratio of the rate of disease in the PI Pens divided by the rate of the disease in the Non-PI Pens
95% CI is the 95% confidence interval calculated for each relative risk, corrected for feedlot and initial weight effects and intra-pen clustering of animal health events using generalized linear modeling techniques. The partially maximized likelihood function was used to calculate the confidence intervals. When convergence of the confidence interval could not be attained using the maximized likelihood function, asymptotic normality was used to calculate the confidence intervals
Values for morbidity and mortality variables are least squares means, expressed as percents, controlling for the effects of feedlot, initial weight, and intra-pen clustering of animal health events