Effects of intranasal or parenteral respiratory vaccination administered on-arrival or delayed in auction-derived feedlot heifers

Abstract

The objective was to evaluate health, performance and serum antibody responses of auction-derived heifers to an intranasal or parenteral MLV administered on d 0 or 28. Three arrival blocks of heifers, initial BW = 459 lb ± 1.7 lb (208 kg ± 27kg; n = 600), were randomly assigned to treatments consisting of 15 pens/treatment with pen as the experimental unit and 10 heifers/pen. Treatments were: 1) Bovilis® Nasalgen® 3 and Bovilis® Vista® BVD on d 0 (NAS0); 2) Bovilis® Vista® 5 SQ on d 0 (VIS0); 3) Bovilis® Nasalgen® 3 and Bovilis® Vista® BVD on d 28 (NAS28); 4) Bovilis® Vista® 5 SQ on d 28 (VIS28). Body weight and blood samples were collected on d 0, 28 and 56. Activity (351.4 vs 354.3 min/d) and rumination time (282.6 vs 285.4 min/d) was less (P < 0.01) for delayed vs arrival vaccinated heifers. A timing χ vaccine χ day interaction existed (P < 0.01) for BRSV- and IBRV-specific antibody titers; VIS28 had the greatest (P < 0.01) BRSV antibody titer on d 56. For IBRV antibody titer on d 28, VIS0 was greatest, NAS0 was intermediate, and VIS28 and NAS28 were least (P < 0.01). Percentage of chronically ill heifers were reduced for arrival vs delayed (1.3 vs 4.7%; P = 0.02) and arrival vaccinated had a reduction in antimicrobial treatment cost ($4.63 vs $7.31; P = 0.02). Data indicate improvement in some health outcomes for the parenteral route and arrival timing of MLV, but performance was not affected.