Abstract

The objective of this study was to evaluate the effect on health and reproductive performance of vaccinating Holstein cows with an intranasal modified live viral vaccine (INV) during the peri-parturient period. Two conventional, free stall dairies and one organic certified dairy were enrolled in the study. In the two conventional dairies cows were vaccinated 18-24 days prior to expected parturition. In the third herd cows were vaccinated 18-24 days prior to expected calving date, within twelve hours after parturition or at both time points. Cattle were blocked based on parity group and expected calving date and randomized to the experimental treatments (vaccination and control) within blocks. Health and reproductive outcomes were monitored and compared to matched, randomly assigned control cows. Results from the first two dairies were used to determine power calculations for the final study in herd 3. Th incorporation of an intranasal viral vaccine program decreased the total cows removed from the herd throughout the lactation, decreased presentation of retained fetal membranes, and lower incidences of pneumonia and mastits. Overall, a greater impact was determined with two doses and, if one dose was administered, the results tended to favor administration at calving