Location: Livestock Issues Research
Project Number: 3096-32000-008-019-T
Project Type: Trust Fund Cooperative Agreement
Start Date: Sep 1, 2018
End Date: Sep 30, 2021
Objective:
The main objective of this project is to evaluate the effect of commercially available Mannheimia haemolytica vaccines on metabolic and inflammatory responses in beef cattle for 7 days following administration.
Approach:
Moderate to high-risk heifers (n=32) weighing between 500 and 700 lbs will be procured from auction markets and transported to the USDA-ARS Livestock Issues Research Unit where they will be acclimated for 7 to 14 days. On day -2, all heifers will be fitted with indwelling jugular catheters and vaginal temperature probes. On day 0, heifers will receive their respective vaccine treatment. Blood samples will be collected from all heifers hourly from -2 hours until 0 hour, and then every other hour from 0 hour until 8 hours. Following the 8 hour blood sample collection, blood samples will be collected at 12, 18, 24, 36, 48, 60, 72, 120 and 168 hours. Following the 168 hour sample collection, the heifers will be processed through the working facility where the jugular catheters and vaginal temperature probes will be removed. Body weights will be collected on day -7, day -2 and on day 7. Health scores will be assigned daily throughout the study. Blood samples will be processed for serum that will be stored at -80 C until analyses of proinflammatory cytokines, acute phase proteins, cortisol and glucose. Following the study, all heifers will be transported to a location to be determined by the collaborator.
