Increased ruminoreticular temperature after simultaneous lumpy skin disease and foot-and-mouth disease vaccination in Hanwoo (

IMPORTANCE: Foot-and-mouth disease (FMD) and lumpy skin disease (LSD) cause major economic losses in Hanwoo cattle. To reduce cost and improve convenience, simultaneous FMD-LSD vaccination is being promoted, yet its effects on ruminoreticular temperature and activity are unclear. OBJECTIVE: To evaluate ruminoreticular temperature and body activity after vaccination, stratified by pregnancy status. METHODS: This prospective observational cohort study investigated ruminoreticular temperature and body activity in Hanwoo cows after experimental administration of FMD and LSD vaccines. Sixty-three Hanwoo cows (pregnant n = 23 [100-175 days], nonpregnant n = 40) were monitored using a rumen-insertable biosensor that records ruminoreticular temperature and activity every 10 min. Groups received FMD, LSD, simultaneous FMD/LSD, or saline (control). Outcomes were analyzed using analysis of covariance with age and parity as covariates. RESULTS: In pregnant cows, simultaneous FMD/LSD vaccination increased ruminoreticular temperature at day 1 and returned to baseline by day 3; single-vaccine groups showed more prolonged elevations. In nonpregnant cows, simultaneous vaccination increased temperature at day 1, normalizing by day 3-4. Body activity did not differ among pregnant groups; in nonpregnant cows, the simultaneous group showed lower activity than single-vaccine groups on some days. CONCLUSIONS AND RELEVANCE: In pregnant Hanwoo cows, post-vaccination temperature increase may enhance the risk of abortion, stillbirth, and premature birth, but this cannot be concluded to be the effect of vaccination. Since vaccination is the sole prevention for infectious diseases, it is unavoidable. Therefore, further research on reproduction related side effects after simultaneous vaccination are needed, and the findings of this study may provide valuable data to support such investigations.