Table 6.
Summary of morbidity data collected in a study to compare 2 vaccination programs in feedlot calves at ultra-high risk of developing undifferentiated fever (UF)/bovine respiratory disease
| Experimental group
|
|||||
|---|---|---|---|---|---|
| Morbidity variable | MLV3-BT2a | MLV4-BT1b | Relative riskc | 95% CId | P-value |
| Initial UF treatment | 327 (16.84)f | 416 (21.44)f | 0.78 | 0.69–0.89 | < 0.001 |
| First UF relapse | 136 (41.59) | 182 (43.75) | 0.94 | 0.80–1.11 | 0.498 |
| Initial NF treatmente | 169 (8.70) | 186 (9.59) | 0.91 | 0.74–1.11 | 0.340 |
| First NF relapsee | 66 (39.05) | 85 (45.70) | 0.86 | 0.67–1.09 | 0.206 |
| Overall chronicity | 69 (3.55) | 113 (5.82) | 0.61 | 0.45–0.81 | < 0.001 |
| Overall wastage | 32 (1.65) | 52 (2.68) | 0.61 | 0.39–0.95 | 0.027 |
Animals in the MLV3-BT2 group received a modified-live viral vaccine containing infectious bovine rhinotracheitis virus (IBRV), type I and II bovine viral diarrhea virus (BVDV), and a Mannheimia haemolytica (MH) and Pasteurella multocida (PM) bacterin-toxoid [Express 3 and Pulmo-guard PHM-1; respectively, Boehringer Ingelheim (Canada) Burlington, Ontario]. There were 6 pens and 1942 animals in the MLV3-BT2 group
Animals in the MLV4-BT1 group received a modified-live viral vaccine containing IBRV, type I BVDV, bovine respiratory syncytial virus, and parainfluenza-3 virus and a MH bacterin-toxoid (Bovi-Shield 4 and One Shot; respectively, Pfizer Animal Health, Pfizer Canada, Kirkland, Quebec). There were 6 pens and 1940 animals in the MLV4-BT1 group
Relative Risk is the ratio of the rate of disease in the MLV3-BT2 group divided by the rate of the disease in the MLV4-BT1 group
95% CI is the 95% confidence interval calculated for each relative risk, corrected for pen and replicate effects using Poisson regression in a log linear model and generalized estimating equations
NF — no fever
Numbers presented are numbers of animals with percentages in parentheses