Procedure—Calves purchased from an order buyer
were delivered to a feedlot to study the effects of
dietary supplementation with 2,000 IU of vitamin E
for 0, 7, 14, or 28 days after arrival. Serum or plasma
Fib, Hap, SAA, and AGP concentrations were
measured on days 0, 7, and 28 after arrival as well
as at the time of treatment for respiratory tract disease
with antimicrobial drugs and after completion
Results—Vitamin E supplementation was associated
with decreased treatment costs. In cattle that were
not recognized as sick or responded positively to 1
antimicrobial treatment, serum Hap concentrations
were significantly lower on days 0 and 7 than concentrations
for cattle that required > 1 treatment. Serum
Hap concentrations and ratios of Hap to SAA on day 0
significantly correlated with the number of antimicrobial
treatments required. Serum Hap concentrations at
the time of initial treatment were significantly lower
for cattle that required only 1 treatment, compared
with those that required > 1 treatment.
Conclusions and Clinical Relevance—Serum Hap
concentrations are of potential value for use in
assessing feedlot cattle that may become ill as a
result of respiratory tract disease and for use in monitoring
treatment efficacy. (Am J Vet Res 2002;
Objective—To identify any adverse effects on health or performance in young dairy calves fed clinoptilolite mixed with milk replacer.
Animals—26 male Holstein calves (1 to 7 days old).
Procedures—Twice daily for 28 days, calves were fed milk replacer with no clinoptilolite (control group; n = 8), 0.5% clinoptilolite (low-dosage group; 9), or 2% clinoptilolite (high-dosage group; 9); each calf consumed approximately 12% of its body weight (based on the replacer solids in the milk replacer mixture)/d. For each calf, subjective health assessments, weight and rectal temperature measurements, and CBC and serum biochemical analyses were performed at intervals. All calves underwent necropsy.
Results—2 calves were euthanized during the experiment because of bronchopneumonia or enteritis. Body weight and average daily gain did not differ among treatment groups. The percentage of monocytes and serum total protein concentration in the low-dosage group were higher than values in the control and high-dosage groups. Compared with values for either clinoptilolite-treated group, BUN concentration was greater in the control group. Serum globulin concentration differed significantly among groups (2.77, 2.50, and 2.36 g/dL in the low-dosage, control, and high-dosage groups, respectively). At necropsy, gross lesions associated with clinoptilolite treatment were not detected in any of the calves.
Conclusions and Clinical Relevance—Even under stressful conditions, clinoptilolite fed at low or high dosages did not affect the performance of dairy calves and had no negative effect on WBC count and blood metabolite concentrations and enzyme activities. Clinoptilolite ingestion was not associated with treatment-specific gross changes.
Objective—To evaluate serum haptoglobin concentration at feedlot arrival and subsequent performance and morbidity and mortality rates of calves that developed bovine respiratory disease.
Animals—360 heifer calves and 416 steer and bull calves.
Procedures—Serum samples were obtained from cattle at the time of arrival to a feedlot (day −1) and analyzed for haptoglobin concentration. In experiment 1, calves were classified into groups with a low (< 1.0 μg/mL), medium (1.0 to 3.0 μg/mL), or high (> 3.0 μg/mL) serum haptoglobin concentration and allotted into pens on the basis of group. In experiment 2, calves were classified as having or not having detectable serum haptoglobin concentrations.
Results—In experiment 1, average daily gain from days 1 to 7 decreased as haptoglobin concentration increased. Dry-matter intake (DMI) from days 1 to 21 decreased with increasing haptoglobin concentration, and DMI typically decreased from days 1 to 63. Total bovine respiratory disease morbidity rate typically increased with increasing haptoglobin concentration. At harvest, no differences in carcass characteristics were observed on the basis of haptoglobin concentration. In experiment 2, cattle with measureable serum haptoglobin concentrations at arrival weighed less throughout the experiment, gained less from days 1 to 7, and had lower DMI from days 1 to 42. Overall morbidity rate was not different between groups, but cattle with detectable serum haptoglobin concentrations had higher odds of being treated 3 times.
Conclusions and Clinical Relevance—Serum haptoglobin concentration in cattle at the time of feedlot arrival was not associated with overall performance but may have limited merit for making decisions regarding targeted prophylactic treatment.
Objective—To evaluate exhaled N2O (eN2O), exhaled CO (eCO), and serum haptoglobin concentrations as diagnostic criteria for bovine respiratory disease (BRD) and determine whether a combination of biomarkers would be useful for predicting health outcomes of heifer calves.
Animals—337 heifer calves newly arrived at a feedlot.
Procedures—Body weights, serum haptoglobin concentrations, and rumen temperatures were determined. Calves (n = 183) were randomly selected for breath sampling. Variables were compared among calves 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 eN2O:eCO2 was lowest at arrival, intermediate at the first and second antimicrobial treatments, and greatest at the third antimicrobial treatment. Ratio of eCO:eCO2 was greater at times of antimicrobial treatment, compared with arrival. Concentration of serum haptoglobin 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 eN2O: eCO2 and eCO:eCO2 and concentration of haptoglobin 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, eN2O, eCO, and haptoglobin concentration were not accurate in predicting occurrence of BRD during a preconditioning program. However, these biomarkers might support the diagnosis of BRD.
Objective—To compare effects of administration of a modified-live respiratory virus vaccine once with administration of the same vaccine twice on the health and performance of cattle.
Design—Randomized, controlled trial.
Animals—612 mixed-breed male cattle with unknown health histories.
Procedures—Cattle were randomly assigned to 1 of 2 treatment groups (single vaccination treatment group [SVAC group] vs revaccination treatment group [REVAC group]) during the preconditioning phase of production. All cattle were given a modified-live respiratory virus vaccine. Eleven days later, REVAC group cattle received a second injection of the same vaccine. During the finishing phase of production, cattle from each treatment group were either vaccinated a third time with the modified-live respiratory virus vaccine or given no vaccine. Health observations were performed daily. Blood and performance variables were measured throughout the experiment.
Results—During preconditioning, no significant differences were observed in performance or antibody production between groups. Morbidity rate from bovine respiratory disease was lower for SVAC group cattle; however, days to first treatment for bovine respiratory disease were not different between groups. No significant differences in body weights, daily gains, or dry-matter intake between groups were observed during the finishing phase. Revaccination treatment group cattle had improved feed efficiency regardless of vaccination protocol in the finishing phase.
Conclusions and Clinical Relevance—Vaccination once with a modified-live respiratory virus vaccine was as efficacious as vaccination twice in the prevention of bovine respiratory disease of high-risk cattle, although feed efficiency was improved in REVAC group cattle during the finishing period.