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Background: The judicious use of antimicrobials in the livestock industry has become a topic of increasing interest over the last few years. Bovine respiratory disease (BRD) is considered mainly a problem of feedlot cattle or dairy calves, but a survey on the use of antimicrobials in California cow-calf operations revealed that BRD is in the top three diseases that ranchers treat most frequently with antimicrobials. There are both viral and bacterial causative agents that are associated with BRD. The pathogenesis of these agents often depends on the immune status of the animals and stress is considered to play major role in exacerbating the problem. In cow-calf operations these stressors can be in the form of management procedures such as processing of calves where they may be castrated, vaccinated, receive ear tags or being branded. Weaning is another stressful event in the life of a calf where the effects can be synergized if the calf is also transported at the same time. Due to the climate and landscape in California, cattle are often transported to different pastures in the summer and winter to take advantage of availability of feed year-round in different parts of the state at different times of the year. Vaccination, immune modulation, improving immune status through mineral supplementation and good colostrum[1] can all play a role in prevention of the disease relative to transportation. In this review we explore the available literature for evidence of effective methods to prevent BRD in cattle in California after transportation.

Objectives:  The objective of this scoping review is to examine and describe the existing literature on methods for the prevention of BRD that can be implemented in cow-calf operations in California and therefore reduce the use of antimicrobials due to BRD.

Design: Primary research on prevention of BRD due to shipping stress will be considered for inclusion. The process for selection and inclusion of the studies will be reported in a flow chart according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses (PRISMA). The results will be summarized in tables and charts describing study types, interventions and outcomes.