Location: Livestock, Forage and Pasture Management Research Unit
Project Number: 3070-31630-008-003-N
Project Type: Non-Funded Cooperative Agreement
Start Date: Aug 1, 2018
End Date: Jul 31, 2023
1. Evaluate prevalence of bovine anaplasmosis in heifers in RFI study maintained by USDA-ARS Grazinglands Research Laboratory, twice per year for a period of up to five years. 2. Evaluate the strain diversity of Anaplasma marginale in RFI heifers. 3. Evaluate the baseline prevalence and A. marginale strain diversity in the management herds into which the RFI heifers will be integrated.
Objective 1. Evaluate the prevalence of bovine anaplasmosis in RFI heifers. The prevalence of bovine anaplasmosis in the RFI heifer group will be evaluated twice per year (in May and October each year). The USDA-ARS GRL will be responsible for collecting samples (blood samples collected into EDTA tubes) and shipped to KSU. KSU Veterinary College Cooperator will determine animal anaplasmosis status using PCR methods. Objective 2. Evaluate the strain diversity of Anaplasma marginale in RFI heifers. The strain of A. marginale will be identified in infected animals (by KSU Veterinary College Cooperatory) by amplifying, cloning and sequencing of the variable region of the A. marginale major surface protein 1a gene. This objective will be completed using the same samples collected for Objective 1. Objective 3. Evaluate the baseline prevalence and A. marginale strain diversity in the herds the RFI heifers will be integrated into. Because the RFI heifers will be divided and integrated into established herds at El Reno, OK, it will be necessary to monitor and determine the baseline prevalence and strain diversity of these herds. This will be completed as described for Objective 1 and 2 and would only need to be repeated if the herds are re-assigned in subsequent years to various management groups. Any seriously ill/deceased animals that are suspect anaplasmosis will have tissue and blood samples collected for evaluation by KSU. Expected outcomes. Determination of temporal changes in anaplasmosis infection status and strain diversity in GRL beef cattle herds.