OBJECTIVE: To evaluate exhaled @entity3727 (e @entity3727 ), exhaled CO (eCO), and serum @entity12314 concentrations as diagnostic criteria for @entity291 @entity1576 (BRD) and determine whether a combination of biomarkers would be useful for predicting health outcomes of heifer @entity291 . ANIMALS: 337 heifer @entity291 newly arrived at a feedlot. PROCEDURES: Body weights, serum @entity12314 concentrations, and rumen temperatures were determined. @entity291 (n = 183) were randomly selected for breath sampling. Variables were compared among @entity291 that remained healthy and those requiring treatment. RESULTS: Body weight at the time of first and second antimicrobial treatments did not differ from that at arrival, whereas body weight at the time of third antimicrobial treatment was lower. Temperature was lower at arrival, compared with that during antimicrobial treatment. Ratio of e @entity3727 :eCO(2) was lowest at arrival, intermediate at the first and second antimicrobial treatments, and greatest at the third antimicrobial treatment. Ratio of eCO:eCO(2) was greater at times of antimicrobial treatment, compared with arrival. Concentration of serum @entity12314 was greatest at the time of the first antimicrobial treatment, lowest at the times of second and third treatments, and intermediate at arrival. Arrival ratios of e @entity3727 : e @entity515 and eCO:eCO(2) and concentration of @entity12314 did not differ among heifers subsequently treated 1, 2, or 3 times. CONCLUSIONS AND CLINICAL RELEVANCE: Although breath analysis was successfully implemented in a research feedlot, arrival rumen temperature, e @entity3727 , eCO, and @entity12314 concentration were not accurate in predicting occurrence of BRD during a preconditioning program. However, these biomarkers might support the diagnosis of BRD.

Evaluation of breath biomarkers and serum @entity12314 concentration for diagnosis of @entity291 XXXX in heifers newly arrived at a feedlot.

@entity3727 :: ('CHEBI:17045', 'Chemical') :: ['N(2)O'] @entity515 :: ('CHEBI:29334', 'Chemical') :: ['CO(2)'] @entity1576 :: ('MESH:D012131', 'Disease') :: ['respiratory disease'] @entity291 :: ('9913', 'Species') :: ['Calves', 'bovine', 'calves'] @entity12314 :: ('280692(Tax:9913)', 'Gene') :: ['haptoglobin']
@entity1576 :: (MESH:D012131,Disease) :: ['respiratory disease']
