Risk factors associated with case fatality and treatment success following initial bovine respiratory disease treatment in feedyard cattle
DOI:
https://doi.org/10.21423/bovine-vol58no2p1-8Keywords:
bovine respirator disease, case fatality risk, first treatment success, risk factors, antimicrobialsAbstract
Bovine respiratory disease (BRD) is an important disease of fed cattle and knowledge gaps exist regarding factors predicting treatment success. The study objective was to identify potential relationships between risk factors known at the time of initial BRD treatment with 3 post-treatment outcomes: first treatment success (FTS), non-cause specific case fatality risk (CFRALL), and cause-specific case fatality risk (CFRBRD). This retrospective analysis used generalized linear mixed models to evaluate relationships between covariates of interest with each outcome. Analysis included 132,521 individual-animal initial BRD treatment records from 14 central U.S. feedyards (May 2017 to Dec 2020) with overall FTS of 67.8%, CFRALL of 10.0%, and CFRBRD of 6.3%. The FTS was associated (P < 0.05) with all covariates except sex, CFRALL was associated with all covariates, and CFRBRD was associated with all covariates except day-of-week treated. Treatments early in the feeding phase (DOF 0-10, 11- 20) resulted in lower (P < 0.05) FTS (49.2% ± 0.8; 55.3% ± 0.8), higher (P < 0.05) CFRALL (12.5% ± 1.3; 12.6% ± 1.4) and higher (P < 0.05) CFRBRD (6.3% ± 1.1; 6.1% ± 1.0) compared to cattle treated on days 21-70. Rectal temperature in the 103.1-104.0 (39.4-40.0 °C) category had higher (P < 0.05) CFRALL (15.3% ± 1.5) and CFRBRD (9.2% ± 1.5) compared to other rectal temperature categories. Specific risk factors including days on feed at treatment, sex and weight at the time of treatment were associated with treatment outcomes. Results can be useful for defining expectations following first treatment for BRD.