Genotyping bovine MHC class II DRB3

Animal studies were performed in accordance with USDA National Animal Disease Center animal care and use protocols. Female Holstein Friesian cows were vaccinated annually beginning at 1 year of age with Vira Shield 6 (Elanco Animal Health, Indianapolis, IN, USA) which includes a BRSV component. Approximately 3mL of blood was collected from the jugular vein of cows into Vacutainer EDTA tubes (Beckton Dickinson, Franklin Lakes, NJ, USA). Genomic DNA was isolated using the QIAamp DNA Blood Mini kit (Qiagen, Valencia, CA, USA) according to manufacturer’s instructions. Genotyping of DRB3 alleles was performed via sequence-based typing (Sanger sequencing) utilizing previously described methods (49 (link), 50 (link)) and restriction fragment length polymorphism (RFLP) as described by van Eijk et al. (30 (link)).