PICO question
 In auction market calves at high risk of developing bovine respiratory disease (BRD), does delayed (14–30 days) vaccination with a modified live vaccine (MLV) for viral respiratory pathogens versus administration of MLV on-arrival (within 24 hours of arrival) to the feedlot, result in a decreased percentage of calves with BRD morbidity diagnosed based on visual signs and rectal temperature >40 degrees Celsius?
 
 Clinical bottom line
 Category of research question
 Treatment
 The number and type of study designs reviewed
 Two papers were critically reviewed. Both are randomised complete block designs
 Strength of evidence
 Weak
 Outcomes reported
 Delaying administration of a modified live respiratory vaccine to feedlot cattle may result in lower BRD retreatments
 Conclusion
 In feedlot calves, delaying modified live vaccine administration for viral respiratory pathogens may result in lower BRD retreatment rates than cattle receiving the vaccine on arrival to the feedlot. Significant statistical data from one study supported this conclusion while another showed numerically less retreatments in calves vaccinated on arrival versus delayed vaccination
 
 How to apply this evidence in practice
 The application of evidence into practice should take into account multiple factors, not limited to: individual clinical expertise, patient’s circumstances and owners’ values, country, location or clinic where you work, the individual case in front of you, the availability of therapies and resources.
 Knowledge Summaries are a resource to help reinforce or inform decision making. They do not override the responsibility or judgement of the practitioner to do what is best for the animal in their care.